Chelsea manager Jose Mourinho believes Didier Drogba is still one of the best strikers in the world.
Drogba, who left the Blues in June 2012, returns to London for Tuesday's Champions League game between his old club and Galatasaray.
"Is he the same player at 36 years old as he was at 26?" asked Mourinho. "Nobody is, but he is certainly still one of the best strikers in the world."
The last-16 tie is finely poised after a 1-1 first-leg draw in Istanbul.
Drogba said he may not celebrate if he scores against his former team-mates.
The Ivory Coast striker netted 157 goals in 342 appearances during an eight-year spell at Stamford Bridge.
With his last kick for the club, he tucked away the decisive spot-kick in the penalty shoot-out at the end of the 2012 Champions League final against Bayern Munich.
Mourinho, who signed Drogba for Chelsea from Marseille in 2004, was given a rousing ovation when he made his return to the Blues dugout in August after a near six-year absence and hopes the Ivorian will experience similar acclaim.
He added: "He is undoubtedly one of the most important players in the history of the club. All Chelsea supporters, we agree with that."
Mourinho also believes that Drogba, who was voted by fans as Chelsea's best-ever player in the club's official magazine in 2012, will return in the future.
"I think it has to happen one day," he continued. "When, I don't know. As a player, as a coach, as an ambassador, next year, in four, five years, in 10 years, I don't know.
"But when a person represents so much to a club and when a club represents so much to a person, and that's the case, I think he has to be back one day."
Chelsea will be the first English side to reach this season's Champions League quarter-finals if they win but Mourinho is taking nothing for granted against the Turkish champions, managed by former Manchester City boss Roberto Mancini.
"Everything is in the balance," Mourinho said. "I think it will be that way as we go into the end of the game.
"I don't think that one of the teams is going to make a result where people at half-time already know who is going to win."
Mancini and Mourinho have not seen eye to eye since the latter replaced the former at Inter Milan in 2008.
But Mancini, who claimed Mourinho only won the Champions League with Inter in 2010 because he inherited a good team from him, said in his news conference that he would be happy to have a post-match meal with the Chelsea boss if his Galatasaray side win on Tuesday.
Asked if he would be in favour, Mourinho said: "No, because I have no interest. After the match I don't do things because I win or because I lose.
"I don't have a meal with somebody that has the same job as I have and this is the only thing we have in common, the fact we both are football managers. Nothing else."
Drogba hopes to mark his return to Chelsea with a Galatasaray victory but plans to keep his emotions in check.
He said: "With all the respect that I have for this club, for the fans and for the players, I might not celebrate, but if we win I'll be happy.
"I have nothing to prove to this club. Everything I had to prove I think I did it with Chelsea. I come here with another team.
"I just want to win the game, I just want to qualify. There's nothing personal against Chelsea, there will never be."