Peterborough United centre-back Jack Baldwin could be out of action for the next two months.
The 23 year-old will have knee surgery on Tuesday (December 6) after experiencing pain in an old injury in recent weeks.
Baldwin was absent for more than 12 months after damaging cruciate ligaments in a home game against Scunthorpe in November 2014.
The £500k capture from Hartlepool had been enjoying a fine run of form after forging a strong central defensive partnership with summer signing Ryan Tafazolli.
McCann said; “Jack has had some discomfort in recent games although you wouldn’t know it from the way he had been playing.
“He will have an operation on Tuesday and he will be out for six-to-seven weeks. He could be back at the end of January or the beginning of February.
“It’s the sensible course of action as I would never ask a player to play through an injury.”
Posh may well seek a new central defender in the January transfer window. Michael Bostwick played alongside Tafazolli in today’s (December 4) FA Cup tie against Notts County, but Ricardo Santos is the only other natural centre-back in the squad.