Former Germany international Thomas Hitzlsperger is training with Everton.
The ex-Aston Villa and West Ham midfielder is currently without a club after leaving Wolfsburg at the end of last season and has been handed the chance to impress David Moyes and his coaching staff.
The 50-cap Hitzlsperger, 30, has also played for Stuttgart and Lazio and is famed for his powerful left-foot.
And Blues assistant boss Steve Round said: "I have been very pleased with him.
"Thomas is a long way off playing but we have given him the opportunity to come in and it is up to him now. We will assess him over the next couple of weeks.
"He seems a really good lad and I don't think I have seen him without a smile on his face. What will determine whether he gets a contract is his fitness. He has had a bad injury and we would want to see that he could sustain training," added Round when speaking to the national media ahead of Tuesday's game at Leeds.
"If he could do that, he would add quality and strength to our squad. He has got a history of playing at the highest level."