With Mohamed Salah breaking his first Liverpool goal record after only five months with the club – claiming the quickest goal return in Reds history after nabbing 14 goals in his first 18 starts – he has established himself as one of the most highly rated players in the Premier League.

While his £34million move from Roma was met with a lukewarm reception in the summer, his performances since then have received glowing reviews and earned plaudits from almost everyone.

One man who might feel a twinge of regret at having underestimated Salah is Jose Mourinho, who signed the Egyptian for Chelsea in 2014 only to give him a handful of starts before deeming him dispensable.

Salah isn’t the first superstar-to-be who Mourinho has underestimated over the years – here are just some of the others who have thrived after parting ways with the Portuguese coach.

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Kevin De Bruyne

Now widely regarded as one of the most complete midfielders in the world, Kevin De Bruyne signed for Chelsea from Genk just before Mourinho returned for his second spell with the Blues. Despite excelling on loan at Werder Bremen in the 2012-13 campaign, the Belgian was given nine senior outings by Mourinho the following season and subsequently decided to leave for Wolfsburg.

“With De Bruyne, if you have a player knocking on your door and crying every day he wants to leave, you have to make a decision,” Mourinho said at the time. “He was not ready to compete. He was an upset kid, his training [was] very bad.”

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Mourinho didn’t last much longer than De Bruyne at Chelsea in the end. The “upset kid” is now excelling under the watchful eye of one of Mourinho’s greatest rivals, with the fact that the credit will go to Pep Guardiola no doubt even more galling for him.

Romelu Lukaku

Romelu Lukaku is another player who, had Mourinho got the most out of him at Chelsea, might have helped his boss save his career at Stamford Bridge. As it was, Mourinho let the ambitious youngster leave for Everton despite his obvious goalscoring talents.

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Now reunited at Manchester United, at least their separation hasn’t been permanent. “His approach was not highly motivated to come to a competitive situation at Chelsea,” Mourinho said when Lukaku left West London looking for more regular starts at Goodison Park. Having signed him for £75million in the summer, Mourinho clearly had no issue guaranteeing game time this time around.

Arjen Robben

It was so long ago that Arjen Robben was a Jose Mourinho disciple that pictures of them together show the Dutchman with a full head of hair. Robben made 105 appearances for Chelsea in the mid noughties, but never quite reached the heights he would with Bayern Munich.

Mourinho allowed Robben to leave the club for Real Madrid in August 2007, just before he himself departed after falling out with Roman Abramovich. Robben had wanted to go, which mitigates Mourinho’s role somewhat, but his former manager must have wished he could have resigned him during his peak years.

Leonardo Bonucci

When Mourinho allowed Leonardo Bonucci to be sold to Genoa from Inter Milan in 2009, there were few protests from fans of the Nerazzurri. The fresh-faced centre-back had made only four appearances for the club and was a relative unknown.

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Eight years later, Bonucci has over 300 appearances for Juventus to his name as well as a whole host of domestic cups and six titles won in the shirt of the Bianconeri. He might not be doing too well with AC Milan at the moment, but Mourinho still failed to spot a defensive gem.

Juan Mata

Much like Romelu Lukaku, Juan Mata has been reunited with Mourinho at Manchester United. Gradually frozen out at Chelsea after the ‘Special One’ returned in 2013, the eventual departure of the two-time Chelsea Player of the Year baffled many fans at Stamford Bridge.

In hindsight, it was perhaps a sign of Mourinho second guessing himself with the collective mind games. Surprisingly, the two men have had a much more productive relationship at Old Trafford and Mourinho has had few qualms about giving Mata opportunities since.