McCann, who missed a large chunk of last season with two knee injuries, is currently undergoing treatment for a knock sustained during the Clarets' tour to Singapore.
He has been out of action since and boss Brian Laws is keen to get a second opinion on the problem, with the new campaign just days away.
Laws said: "We can't really put a finger on what is exactly wrong with Chris until he sees the specialist and he looks at the scans.
"Let's see what the outcome is when he sees a specialist next week, just to make sure that he's happy with everything.
"He is still in training and still working hard. We're just keeping him out of the contact zones with other players."
Michael Duff, meanwhile, believes Burnley's squad is stronger now than when they won promotion two seasons ago.
The Clarets reached the top flight via the play-offs in 2008/09 and are gearing up for another promotion push after relegation last term.
Laws has signed Ross Wallace, Chris Iwelumo, Dean Marney and Lee Grant, making Burnley among the favourites for promotion with bookmakers.
Defender Duff said: "This squad is definitely as strong, if not stronger, than two years ago.
"We played 11 versus 11 in training this week and both teams could do well in the Championship, so hopefully that shows we've got strength in depth in the squad.
"Hopefully we can do well because there is certainly great competition for places right throughout the squad."