Owen Hargreaves concedes he will not be able to rush straight back into action with Manchester City.
The injury-plagued former England midfielder is hoping to revive his career at City after being released by rivals Manchester United in the summer.
The 30-year-old has signed a one-year deal at the Etihad Stadium but, after being restricted to just four appearances in the last three seasons, accepts he is short of match fitness.
That means a return to action against former club Bayern Munich in the Champions League later this month is unlikely.
Hargreaves told the club's website, www.mcfc.co.uk: "It's important that you get back into a rhythm of playing football, and I haven't done that for a while.
"There's tons of games to come this season in various competitions.
"I've never not played in the Champions League. It's pretty much been standard for me every season.
"Bayern is a wonderful club - I had a great time there and won the Champions League.
"They are going to be tough opposition and it will be an exciting game for the club."
Calgary-born Hargreaves made his name with Bayern and shone in the 2006 World Cup for England before joining United in an £18million deal the following year.
He had attracted interest from West Brom after United opted not to renew his contract but feels joining City, expected to mount a serious Barclays Premier League title bid this season, is a greater challenge.
Hargreaves, aware competition for places will be fierce, added: "I like to measure myself agains the best and I've always taken on challenges - I left Canada for Germany as a kid, I've left comfortable situations.
"It's a fantastic group of players here, and I hope that I'll be a good addition to these guys to help out.
"I've lived in Manchester for four years and this move just fits. You've got to trust your instincts."
Hargreaves will play alongside Carlos Tevez this season after the Argentina forward's much sought-after move failed to materialise.
The 27-year-old, City's top scorer and talisman last season, said he would never return to Manchester, not even on holiday, as he tried to force City to sell him over the summer.
But after yesterday's transfer deadline, Tevez will now be staying at City until the January window at least.
Having cited a desire to move nearer to his family in Argentina as his chief reason for wanting to leave, Tevez has now been joined in Manchester by his wife.
His advisor Kia Joorabchian told talkSPORT: "There were a couple of offers in for him but obviously he is an important player for City and they won't let him go for any (old) price.
"We couldn't quite match what City wanted.
"But at the end of the day - as Carlos said at the end of the season - professionally, he is happy at the club.
"He is happy in the situation - it was more to do with his family really.
"He has managed to convince his wife to come over for a while at least.
"If she manages to settle in hopefully in the next four or five months, maybe he will settle down and things will be fine."
Tevez was close to rejoining Brazilian club Corinthians in July but the move collapsed.
Inter Milan later made approaches but City were not satisfied enough to do business and the possibility of a swap involving Wesley Sneijder ended when the Manchester club bought Arsenal's Samir Nasri.
The willingness to consider Inter raised eyebrows given Tevez's wish to move closer to Argentina, but Joorabchian said: "Carlos is the kind of player who adapts everywhere he goes.
"He adapts to every league and has won every major domestic competition he has ever played in.
"He himself has no problem with it but, culturally, Milan or Spain would be easier for the wife to adapt to.
"She could get around and communicate better. That was the major problem but the next four or five months will be very important."
Joorabchian admitted Tevez's wage demands - he is currently thought to be on £286,000 per week - limited the number of clubs that could be considered.
He said: "You can get down to teams like Inter, who made a couple of offers, and maybe Real Madrid.
"You can really narrow it down to four or five teams in the world that could afford him."