The England international picked up the problem during Saturday’s 0-0 draw with Leicester City, and although Conte is optimistic the injury suffered by Cahill is not severe, the length of absence the captain faces is uncertain.
“Cahill was a muscular problem, but not a serious problem,” Conte said after the match. “It’s good news. Now I don’t know the time he needs to recover.”
Even though Cahill is unlikely to be out for a lengthy spell, the news still comes as a blow to Chelsea ahead of some crucial cup games against Norwich and Arsenal.
The Canaries visit Stamford Bridge in an FA Cup third round replay on Wednesday, while the Carabao Cup semi-final second leg against Arsenal is also on the horizon.
Andreas Christensen, who has just penned a new deal, replaced Cahill against the Foxes and is expected to deputise going forward.
Colchester will hand late fitness tests to Ryan Jackson and Brandon Comley prior to their clash with Yeovil.
Arsenal secured their place in the quarter-finals of the Europa League following their 3-1 defeat of AC Milan at the Emirates Stadium on Thursday.
Danny Welbeck scored twice against AC Milan to toast his England recall by sending Arsenal into the last eight of the Europa League.
Ipswich striker Joe Garner will not play again this season after it emerged he suffered a fractured skull against Sheffield United last week.