Welcome to ESPN's Insider Notebook, featuring contributions from our reporters across the top leagues around the world.

In this edition, there's the latest on Arsenal's investigation into their record £72 million signing. Plus: Barcelona start their search for a new boss.

Jump to: Barca hunt for new boss | Mourinho and Levy's transfer market battle | Big interest in ex-Barca rookie | Ceballos' Real return | Man United's plan to stop Europa boredom | MLS new boys need a spot for Dominguez

Arsenal investigate £72m Pepe transfer

Arsenal's efforts to streamline and improve their operations has extended to an internal investigation into whether they overpaid for £72m club-record signing Nicolas Pepe.

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Sources have told ESPN the deal has been re-examined as part of the wider recruitment overhaul which led to the departures of a host of scouts including Francis Cagigao, Brian McDermott and Brian Clark as well as several more senior employees based throughout Europe.

Pepe ended his debut season in England with eight goals and 10 assists across all competitions; a satisfactory return despite some inconsistent form. There is said to be no sense of regret at signing the 25-year-old but many people within the game were surprised at the size of the fee Arsenal paid to Lille, especially coming from a club where finances are notoriously tight. The Gunners paid £20m up front but have committed a further £52m over the next five years, the first instalment of which is due this summer. The depth of that commitment has led to a review of the scouting reports and negotiating process which led to such a big deal being sanctioned.

Pepe attracted interest from a number of Europe's top clubs after impressing in Ligue 1 but sources have told ESPN that individuals working for other clubs who became involved in preliminary talks with Lille were taken aback by the amount Arsenal eventually paid.

Technical director Edu joined the club three weeks before Pepe signed for Arsenal -- he held up Pepe's shirt with the winger at his unveiling -- but the bulk of the work on the deal had already been done. Former head coach Unai Emery has previously stated he preferred to sign Wilfried Zaha but Crystal Palace wanted the majority of a similar fee up front and Arsenal opted for Pepe instead.

Edu has led a drive to overhaul Arsenal's recruitment at all levels -- Ty Gooden, Arsenal's leading scout in France, has also been released -- in the belief that a global network is less important than data-driven analysis and forging relationships with key agents.

With COVID-19 a contributing factor to 55 non-playing staff redundancies and further pressure on a modest summer transfer budget, Edu is determined to make every penny count. -- James Olley

Barca start search for new boss

Barcelona coach Quique Setien will lead the team in Friday's Champions League quarterfinal against Bayern Munich but the club have already begun sounding out possible replacements, sources have told ESPN.

The overriding feeling at Barca is that Setien, hired in January, has failed to win the dressing room around because of his relatively limited achievements as both a player and a coach. They would want their next appointment to be a name that garners immediate respect among the players.

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Ronald Koeman has been sounded out because of his history with the club and he remains a candidate. Sources at Barcelona remember how he did a good job of clearing out an ageing squad at Valencia in 2007, but there are concerns about his pragmatic playing style. He recently bought a house in Vallvidrera, next to Barcelona, although he has always stressed his desire to remain in charge of the Netherlands for the European Championships, which will take place next summer.

Former Tottenham coach Mauricio Pochettino is another target. However, his past with Barca's rivals Espanyol and previous comments about accepting the Barca job could complicate any appointment. Xavi Hernandez is the obvious target but an immediate return is unlikely after he rejected the chance to in January

Sources explain that the profile of coach wanted is clear, but there is no outstanding option for the job. -- Samuel Marsden and Moises Llorens

Mourinho and Levy give and take in the transfer market

It felt inevitable from the moment Jose Mourinho was appointed Tottenham head coach that he would clash with chairman Daniel Levy given their contrasting approaches to the transfer market, yet both are giving ground to make things work so far.

Sources have told ESPN that while Levy was excited by the prospect of academy graduates Kyle Walker-Peters and Troy Parrott breaking into the first team next season, Mourinho did not rate either player. Walker-Peters has now left for Southampton and Parrott is already out on a season-long loan at Championship side Millwall.

The signing of Pierre-Emile Hojbjerg from Southampton, however, is evidence of the pair working in tandem given the midfielder plugs a gap in Mourinho's squad at a price (around an initial £15m) compatible with Levy's fiscal conservativism. Hojbjerg is not the big name some Spurs supporters -- or even Mourinho himself -- may crave but a degree of compromise is required and both the Spurs boss and Levy have shown a willingness in that regard.

Mourinho left Manchester United citing a lack of support from those above him. These are still relatively early days in his tenure -- and Mourinho must back up these judgment calls with results -- but he can have little complaint in that regard to date. -- James Olley

Ex-Barcelona rookie attracting big Premier League interest

A string of Premier League clubs want to sign former Barcelona defender Xavier Mbuyamba, various sources have told ESPN, with Chelsea among those keen to land him.

Mbuyamba, 18, has been inundated with offers from English and German clubs after agreeing to the early termination of his contract with Barca this summer.

The Dutch youth international only joined the Catalan club last summer and was one of the standout performers in their under-19 team last season, even training with the first team once. However, broken promises over the number of minutes he would get with the B team next season led to a breakdown in the relationship between the player's camp and the club.

Premier League and Bundesliga clubs quickly registered their interest in the 6-foot-5 centre-back but Chelsea, who had him on trial last summer before he signed for Barca, have always been the frontrunners.

Meanwhile, Chelsea remain favourites to land Real Madrid full-back Sergio Reguilon, sources have told ESPN, but they face competition from several clubs for his signature.

The 23-year-defender -- now represented by Kia Joorabchian -- is still on loan at Sevilla, starting in their Europa League win over Wolves on Tuesday.

Madrid are keen to sell to raise funds for incoming transfers and want around €25m, making Reguilon a bargain alternative to Chelsea target Ben Chilwell. But sources have told ESPN that while Chelsea have held talks, Frank Lampard's team are no longer the only ones in the race for Reguilon. -- Sam Marsden, Moises Llorens, Alex Kirkland and Rodrigo Faez

Ceballos' Madrid return raises eyebrows

Reports in Spain that Dani Ceballos will return to Real Madrid this summer came as a surprise to those familiar with his frosty relationship with coach Zinedine Zidane, sources have told ESPN.

The pair haven't seen eye-to-eye in the past, and another season on loan at Arsenal was looking most likely before claims this week that the midfielder will rejoin Madrid for preseason training.

Ceballos' performances this year, becoming a key player for the Gunners and starting in their FA Cup final win over Chelsea, haven't gone unnoticed at the Bernabeu. Madrid are looking to refresh their team but they have little money to spend amid the uncertainty caused by the coronavirus crisis. They have already recalled Martin Odegaard from his loan at Real Sociedad and while Zidane has always been a fan of him, he has had mixed feelings about Ceballos, handing him just four La Liga starts in 2017-18. The coach would need to be persuaded to find a role for the 24-year-old, and Ceballos would need assurances about playing time ahead of next summer's Euro 2020 tournament and the Olympics.

The suspicion remains that bringing Ceballos back would be a strategic move from Madrid, forcing interested parties to increase their bids while leaving open the possibility of a stay if Zidane is convinced and other departures create space in the squad.

Failing to secure Ceballos for another season would be a big setback for Arsenal coach Mikel Arteta, after the player shone following the restart of football amid the coronavirus. -- Alex Kirkland and Rodrigo Faez

Man United's plan to stop Europa League boredom

Manchester United could be in Germany for two weeks if they make it all the way to the Europa League final and the club have put plans in place to stop the players getting bored, sources have told ESPN.

Ole Gunnar Solskjaer's squad are having their movements outside the team hotel in Cologne restricted by UEFA due to the ongoing pandemic and so to keep the players entertained, United have brought their own games room with them. It's fully stocked with a pool table, table tennis, PlayStations and even an indoor basketball game that you would usually only find in an arcade.

? @JesseLingard ? Brandon Williams ?

Just a little insight into how the lads are spending their downtime in Germany ?#MUFC #UEL

— Manchester United (@ManUtd) August 12, 2020

With five days between the 1-0 quarterfinal win over FC Copenhagen and the semifinal clash with Sevilla on Sunday, sources have told ESPN that it is already getting a lot of use. -- Rob Dawson

MLS new boys Austin FC need a home for Dominguez

A month after signing their first player, MLS expansion side Austin FC may be adding another -- though they'll need to find a spot for him first.

Austin's latest target, according to the Austin-American Statesman, is Independiente and Paraguay international winger Cecilio Dominguez. The Argentina-based club publicly stated that a deal is done, and even mentioned that the transfer fee is $4m, but that has been denied by Dominguez's agent, Diego Serrati. Serrati is also the agent of Rodney Redes, who became Austin's first signing back in July.

Dominguez, 26, has spent the past two seasons with Independiente, scoring eight goals in 41 league and cup appearances. He has previously been on the books of Liga MX side Club America, as well as Cerro Porteno and Sol de America in his native country. At international level, Dominguez has made 17 appearances for Paraguay, but has yet to score.

Austin isn't set to begin play in MLS until next season, and finding a landing spot for Dominguez until then is complicating matters. Independiente don't want him on loan, though it's possible Dominguez could return to either of his two former clubs in Paraguay. -- Jeff Carlisle