Leandro Trossard was Arsenal's "Plan B" when he arrived at the Emirates in a transfer worth up to £27 million from Brighton & Hove Albion in January. But the winger might just prove to be the most significant Premier League signing of the season and the one who delivers the key ingredient to winning the title.

Of course, if Manchester City overhaul the Gunners to claim a third successive title during the final two months of the campaign, Erling Haaland's incredible goal tally -- already at 42 in 37 games in all competitions -- will ensure that the Norway forward will be regarded as the most impactful transfer. But Trossard's performances for Arsenal since signing for Mikel Arteta's team have been so significant and decisive that the 28-year-old may turn out to be the man who seals their first Premier League title since 2004.

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The irony of Trossard's contribution is that but for Chelsea's readiness to outbid their London rivals for Shakhtar Donetsk winger Mykhailo Mudryk in January, he would likely still be at Brighton, with Mudryk playing in Arsenal red rather than Chelsea blue. Arsenal had made all the running on Mudryk, scouting the 22-year-old Ukraine international for months and registering their interest with Shakhtar so early that it seemed a deal would be done in the opening days of the January window. The player showed he was keen to push the transfer himself with a series of social media posts highlighting his affection for the club. But despite making three bids for Mudryk, Arsenal missed out on their top target because Chelsea simply offered to meet Shakhtar's €100m valuation and the player headed for Stamford Bridge instead.

Chelsea's gain has not turned out to be Arsenal's loss, however, because Trossard has exceeded expectations at the Emirates and also vastly outperformed Mudryk, who has endured a difficult start to his career at Chelsea. After just 11 Premier League appearances for Arsenal, Trossard has registered seven assists. Only Bukayo Saka has more for Arteta's side this season, and he has managed his 10 assists in 29 games. Midfielder Martin Odegaard has seven, just like Trossard, but the Gunners' captain has taken 28 games to reach that number. To put Trossard's contribution into a wider context, Kevin De Bruyne leads this season's Premier League assists table with 13 and the Manchester City midfielder has played 29 games.

Trossard, a dominant force down the Arsenal left flank, has also created 15 chances in his brief time at Arsenal. His value to Arteta is that the manager knows he has a player who will make at least one chance a game and that it will be a good chance, judging by the fact that almost half of them lead to goals. By comparison, Mudryk has contributed next to nothing at Chelsea. He has managed just one assist in eight appearances and created only three chances for his teammates, and the 22-year-old is still waiting to score his first goal. Trossard, meanwhile, opened his account in a 1-1 draw against Brentford in February, and the Belgium international has put in a several shifts as a makeshift centre-forward.

For Mudryk, the move to Chelsea might turn out to be a sliding doors moment in his career. Had he signed for Arsenal, he would have been parachuted into a team riding high at the top of the league with a manager who not only wanted him, but also one who was totally secure in his role. At Chelsea, Mudryk has had to adjust to the Premier League while playing for a team that has been struggling desperately for form with a group of players thrown together by the new ownership group. And, in terms of his manager, Graham Potter's firing earlier this week had looked likely for a while and it is debatable as to how much influence, if any, he had in identifying Mudryk as a target.

Football moves on quickly, though, and Trossard has taken full advantage of the opportunity afforded to him by Mudryk's move to Chelsea. And Arsenal have struck lucky by ending up with a player who was already established in the Premier League rather than one who had to leave his homeland as well as his club for the first time.

But luck is only a portion of the story. Arsenal had clearly identified Trossard as a backup option should Mudryk not arrive. His signing, just like those of Gabriel Jesus and Oleksandr Zinchenko from Manchester City last summer, highlights the improvement in recruitment at the Emirates since Edu's appointment as technical director in 2019, prior to his elevation to sporting director last November.

Anyone can identify a "Plan A" and hope to carry it through, but it is the contingency plan that points to the research and work behind the scenes. And Arsenal's "Plan B" has so far been so successful that it has given them a turbo-boost towards the title.