Chelsea fans must be scratching their heads wondering how their club allowed Mohamed Salah to slip through the net at Stamford Bridge.

Jose Mourinho signed the Egyptian winger from FC Basel in January 2014, convincing the Blues to fork out £11 million for his services, but never gave him a fair crack of the whip.

Salah made 11 appearances during the second half of the 2013-14 campaign and then eight more the following season.

He was also loaned to Fiorentina during the 2014-15 campaign but, despite scoring nine goals in 25 matches, failed to convince Mourinho of his quality and was loaned to AS Roma at the start of the 2015-16 season.

Salah impressed on loan at Roma but wasn’t retained by Chelsea, who offloaded him to the Italian outfit on a permanent deal in August 2016.

Salah has been a revelation for Liverpool

Less than 12 months later, Salah is back in English football with Liverpool - and he’s been an absolute revelation at Anfield.

The 25-year-old has scored a magnificent 19 goals in 24 matches for the Reds this season and will be a serious contender for the PFA’s Premier League Player of the Year award if he can sustain his current form for the rest of the season.

Drogba reveals what Salah text him at Chelsea

Salah was voted the BBC African Footballer of the Year for 2017 on Monday and his former Chelsea teammate, Didier Drogba, has revealed the texts they exchanged when Salah was at his lowest ebb.

"There was time when he was texting me: ‘I don't score, I don't know why’” Drogba revealed, per BBC Sport.

“I said: ‘It is just a matter of time and confidence.’”

How nice that Drogba was there for Salah when he needed some support. His reply was perfect, too.

"When you have the confidence everything can happen and you can see now that he is scoring goals,” Drogba continued.

"I saw how he improved through the years. He had to go to Italy to perform and then come back to England show that he is the player we always believed he was.

"What he has done with the national team as well being able to qualify the country in a very difficult game I think he deserves it."

Drogba: Salah's celebrations show his confidence

Drogba also believes that Salah’s way of celebrating goals shows the amount of confidence he’s currently playing with.

"He's becoming a boss and a leader we've seen it in the national team and seen it at Liverpool,” Drogba added.

"I can tell by his celebrations that he knows what he's doing now, he's not going crazy but just sticking his tongue out to say 'yeah it's me'."

Drogba tips Salah to star in Russia

The Chelsea legend has also tipped Salah to be one of the stars of next summer’s World Cup finals in Russia.

"He can bring a lot of his leadership and his experience, that he is learning at Liverpool and with the national team [to the team in Russia]," he concluded.

"You know for him playing in a lot of big competitions will help him to be among the best players in Europe and during the World Cup

"Mo Salah on his own cannot win the World Cup but if all his teammates are at the level the continent expects them to be, then Mo Salah can be a fantastic player and be one of the stars in this competition."