Update: Chelsea have said that they expect Lampard to be ready to play on Monday.
Much of Chelsea's recent blip in form could be attributed to Frank Lampard's long-term absence from the first side. The Blues have long been reliant on the England midfielder's ability to unravel defences through clever passing, free kicks, and late runs, and when they field a team without Lampard they're often accused (fairly accurately) of lacking creativity in the final third. Although Lampard is now fit and playing regularly once more, he's been reported as saying that the tendon tear he suffered while rehabbing groin surgery is a long-term problem that won't ever go away, something that concerned fans worried about the aging star's health. However, a more short-term problem has arisen.
According to the Daily Mail, Lampard limped out of Wednesday's training session with a calf injury of some kind. The severity of the issue is currently unknown - Chelsea will be doing further tests on it tomorrow - but the 20-goal midfielder is at the very least a major doubt for Monday's trip up to Bolton. The Blues have been getting used to life without Lampard, who until this season had been something of an iron man for the club, but with injuries also striking down midfield cover Yossi Benayoun, Yuri Zhirkov, and John Obi Mikel, there's very little room for manoeuvre with the roster.
If Lampard does miss time and Mikel isn't ready to start, we may see either Florent Malouda or Josh McEachran in the midfield for the match against Bolton Wanderers. If Carlo Ancelotti does decide to go with McEachran on Monday, it's possible that he withdraws the youngster from Thursday's FA Youth Cup game against Arsenal at Stamford Bridge so as to minimise the risk of him being injured and leaving the Blues with no cover at all in the middle of the pitch.
Hopefully the problem does not prove serious and Frank is able to play a role in the next match. But given his health concerns all season, there's plenty of reason to worry about this latest blow. The good news is that it's not his groin again. We'll keep you informed as we hear more.