His return to Stamford Bridge on Tuesday, however, left the former Germany captain with a bittersweet aftertaste.
Ballack, who will be 35 later this month and had spent four seasons at Chelsea, winning three FA Cups and a league title, was honoured by the London club prior to the game on Tuesday.
But that was the last bit of good news he would have for the evening, missing a huge chance for the lead in the 57th minute and being taken off a little later, 37 seconds before his team conceded the first goal. They went on to lose 2-0.
"I keep thinking about that missed chance because had I scored it could have been completely different for us," the midfielder told reporters in the early hours of Wednesday.
"Unfortunately it did not go in and nothing can change that."
Ballack was a surprise inclusion in the squad after being mainly relegated to the bench this season.
His experience and knowledge of Chelsea seemed to have worked in his favour when coach Robin Dutt compiled his starting line-up for Leverkusen's first champions League game in more than six years.
It almost paid off when he found himself inside the box on 57 minutes with the score 0-0 and only goalkeeper Peter Cech to beat.
Ballack, whose long career includes losing a Bundesliga title on the last match day with an own goal, losing the Euro 2008 and the 2002 World Cup final as well as two Champions League finals with Leverkusen and Chelsea, failed to elude Cech and Chelsea went on to score twice and win the game.
Asked why he had taken Ballack off despite a very good performance, Dutt said: "He was tired."
"No, not really," Ballack responded. "I actually felt very good. But that is the coach's decision and you have to respect it. But I think I can last the full 90 minutes."
With Racing Genk drawing 0-0 with Valencia in the other group match, Ballack sounded hopeful his team could still go for a second place finish to advance in the competition.
"We played very well but I know from my own experience how difficult it is to get anything here. Now we have to get the points we need from the other games."
