It has been a hugely frustrating period for the midfielder who made his last appearance in the defeat to Liverpool back in September.
"I start my training in the morning with the team, so I am back!" said the Finland international on Monday afternoon. "I've already done ball work and tackling so I am ready to rejoin the squad," he added, before admitting that his absence from the European nights since the trip to Prague has been a big regret for him.
"Every game you miss it is hard to accept, but European competition is something special. Hopefully there will be plenty more to come."
Teemu Tainio was back in training on Tuesday morning after missing 11 games following hernia surgery.