#2 Kieran Trippier

One of the more surprising moves of the summer saw Tottenham and England right-back Kieran Tripper move to Spain’s La Liga with perennial title challengers Atletico Madrid. At the time, the move felt like a smart one for Spurs; they’d made a huge profit in selling a player they bought for just £3.5 million for around £20 million, and to add to that, Trippier appeared to have peaked at the 2018 World Cup and had struggled for form throughout 2018-19 campaign.
However, just over six months later, Spurs fans – and the club’s new boss Jose Mourinho – would probably love to have Trippier back in north London. Not only has the right-back been able to regain his spot with England’s national side, but he’s also been on tremendous form for his new club in Spain.
Trippier has appeared in 16 of Atletico’s 23 league matches, and thus far his new side have conceded just 15 goals in La Liga, compared to 32 conceded by his old team in the Premier League. What’s more, Trippier has also maintained the kind of pinpoint delivery that made him so highly rated in the first place, registering four assists in all competitions with a Man of the Match-level performance coming in a Champions League game against Juventus.
Given his replacement at Spurs – Serge Aurier – has struggled for consistency and has made a number of rash mistakes during the season, there can be little doubt that the north London side regret selling the England international despite making a profit.
#3 Idrissa Gueye

Everton were once again one of the Premier League’s biggest-spending sides during the summer, spending millions to ink the likes of Andre Gomes, Alex Iwobi and Moise Kean, but the Toffees also made a big sale when they signed off the departure of holding midfielder Idrissa Gueye to Paris Saint-Germain for a fee of around £30 million.
However, since the Senegalese midfielder’s departure, Everton have largely struggled for traction in the Premier League – with an upturn in form only beginning once manager Marco Silva was fired and replaced by Carlo Ancelotti. Midfield in particular has been a weak point for them, with Morgan Schneiderlin and new signing Fabian Delph not looking up to scratch.
It’s in this area that the Toffees must miss Gueye greatly; the tough-tackling midfielder scores far more highly in practically every statistic in comparison to those who have attempted to fill his boots at Goodison Park, and it’s hard not to imagine that Everton may not have struggled so badly under Silva had they not sold him.
Sure, the Senegalese international is now 30 years old – meaning a £30 million fee was a decent return – but with Everton now pushing for a European slot next season, the Toffees must wish they still had one of the Premier League’s most consistent performers.