When Manchester United completed the £37.1million club-record signing of Juan Mata from Chelsea, you'd be hard pushed to find a Red Devils supporter that looked negatively upon the deal.
After all, the Spain international is a truly world-class talent, and one that will improve David Moyes's side immeasurably over the coming years.
However, glancing across at Stamford Bridge, and more specifically focusing on Jose Mourinho's £21million capture of Nemanja Matic from Benfica, and it's difficult to ignore the fact that the Premier League champions made a glaring mistake, and signed the wrong Chelsea midfielder.
Since his return to west London in January, the Serbian international has impressed in his holding midfield position. Good on the ball and hard in the tackle, the 25-year-old is tailor-made for the Premier League, and has added some much needed grit to the Chelsea team, allowing Mourinho's more creative players the freedom to express themselves further up the pitch.
Matic is exactly the sort of player that Manchester United are currently lacking, and would have been a perfect foil for Michael Carrick in that deep-lying midfield role at Old Trafford.
Moyes is blessed with an array of attacking midfield talent, with the likes of Wayne Rooney, Shinji Kagawa and the emerging Adnan Januzaj all able to support Robin van Persie, Danny Welbeck or Javier Hernandez in attack, and that's before you even consider wide-men Ashley Young, Antonio Valencia and Nani.
Mata's arrival has further strengthened an area of the squad that is already brimming with creativity, whilst there remains a dearth of protective options in the middle of the park.
With Marouane Fellaini sidelined and Darren Fletcher still getting back up to speed following a lengthy period out injured, that leaves Tom Cleverley, who has been heavily criticised for a number of under-par performances this season.
Centre-back Phil Jones has been utilised in a more advanced position in some games this season, but it's clear that his long-term future lies at the heart of Manchester United's defence.
It begs the question why Moyes didn't prioritise signing a central midfielder in the mould of Matic in January, particularly when he was clearly available for transfer.
The oversight could have massive repercussions for the club, with Manchester United currently lying in a lowly seventh place in the Premier League table, and at risk of missing out on the Champions League next season.
They will likely look to resolve the issue when the transfer window reopens this summer, but it's a massive gamble delaying the decision to strengthen when the need for reinforcements is obvious.
Chelsea have improved their chances of winning the Premier League title with the acquisition of Matic, while Mata's magic might not be enough to save Manchester United's season.