PERTH, Australia -- After landing in Perth to begin preparations for the new campaign, Manchester United manager Ole Gunnar Solskjaer puffed out his cheeks and said, "It's been a long summer."

He said it with a smile, but it was a reference to the problems that have piled up since the end of last season.

Star midfielder Paul Pogba says he wants to leave. Romelu Lukaku wants to join Inter Milan. Victor Lindelof's agent says the Swede could be tempted by a move to Barcelona.

- United stunned by £50m Longstaff price
- Lukaku misses Man Utd training amid Inter links
- Rumour Rater: Man United back in for Milinkovic-Savic?

Two young players have arrived -- Daniel James and Aaron Wan-Bissaka -- but attempts to add more new signings have been hit by rival clubs slapping what United believe are unrealistic price tags on their players. Leicester want £90 million for Harry Maguire. Sean Longstaff has made just nine Premier League appearances but is valued at more than £50 million by Newcastle.

Solskjaer and his staff will spend more than three weeks on tour among visits to Australia; Singapore; Shanghai; Oslo, Norway; and Cardiff, Wales, and the Norwegian has a laundry list of problems to solve before the important stuff starts against Chelsea on Aug. 11.

1. Paul Pogba

It is the issue that will dominate until the transfer deadline. The midfielder said he wants a "new challenge" after three seasons at Old Trafford and is being chased by both Juventus and Real Madrid. United want to keep him and, speaking to the media at the WACA cricket ground Wednesday, Solskjaer was quick to reference the 26-year-old's contract, which still has three years to run. Three days later, the manager implied Pogba could even be a captaincy candidate. United -- as Solskjaer has pointed out -- do not need to sell, but he must decide whether he can get the best out of Pogba this season. The France international's attitude in training during the tour will tell him a lot.

2. How to approach the Europa League

Solskjaer has brought a host of young players to Australia, including Mason Greenwood, Angel Gomes, James Garner, Tahith Chong and Axel Tuanzebe. The United manager has hinted he might use the Europa League to give them more experience next season, and the six tour games -- starting with Perth Glory on Saturday -- will be a good indicator of whether or not they are up to it. Playing on Thursday nights isn't ideal, but United can't afford to throw away the Europa League because it's inconvenient. It might be their best chance of getting back into the Champions League.

3. Challenges at the back

United have brought six centre-backs with them to Australia -- Lindelof, Eric Bailly, Phil Jones, Chris Smalling, Marcos Rojo and Tuanzebe -- while continuing their pursuit of another one, Maguire. Solskjaer cannot accommodate them all. Lindelof was one of United's best players last season, and both Jones and Smalling have signed new long-term contracts. Rojo insists he has been told he is part of Solskjaer's plans, while Bailly, when fit, is one of the most natural defenders in the squad. Still, if Maguire comes in, it is likely at least one will have to leave, and it will be down to Solskjaer to decide who that is.

4. Is it a risk to let Lukaku go?

Lukaku wants to join Inter Milan and United are open to him going if the Serie A side can stump up £80 million. The striker has split fans since arriving from Everton two years ago, but he is still the closest thing in the squad to guaranteed goals. He has averaged nearly a goal every two games at Old Trafford and it would be a risk to let him leave without bringing in another proven goal scorer as a replacement. There aren't enough goals in the team as it is.

5. Where the squad needs work

After finishing sixth last season, you could argue that every area of the squad needs work, but there is a significant issue in the centre of midfield. Solskjaer relied heavily on a midfield three of Pogba, Nemanja Matic and Ander Herrera during his impressive run of results after taking over from Jose Mourinho, but Herrera has gone and will need to be replaced. Andreas Pereira has been handed a new contract, and it might be that the Brazilian is asked to play a more prominent role this season along with fellow academy graduate Scott McTominay. More will be expected of £48 million Fred, too, after a hit-and-miss first season in England, but he is yet to join the squad in Australia after staying behind for personal reasons.