Spartak Moscow's Aiden McGeady is proud about the way Celtic have profited from his departure as the two clubs prepare to face each other.
The Parkhead club sold the popular Irish international for a fee thought to be around £9million in 2010, with manager Neil Lennon subsequently reinvesting the money to help rebuild his squad.
In a strange twist of fate the two clubs were drawn together in Group G of the Champions League, and the 26-year-old is delighted at Celtic's success since his departure.
"I have a real sense of pride that the money Spartak paid for me helped Celtic out," he said. "That's a nice thing to look back on as that fee has meant a lot to the club. You just have to look at the mess Rangers are in just now to appreciate that. The money Celtic got has obviously gone a long way to helping stabilise the club.
"It's funny that Lenny said he went out and bought a lot of players on the back of me leaving but that does makes me pretty proud.
"Right now Celtic are a good team with a lot of good young players. They generally go out and buy young players with the aim of selling them on for a greater price.
"I'm glad I kind of became the first one Neil Lennon did that with."
However Spartak's position at the bottom of their group, following their 3-2 defeat by Barcelona, means that McGeady will put friendship firmly to one side in the Luzhniki Stadium.
"I'll be playing against people who are my friends but I need to forget that," he said.
"I've always tried to do my best. Now I am a Spartak player, I will be doing everything I can to help us win."
