The reigning Premier League champions will be without the centre-back for Tuesday evening's clash with QPR at Loftus Road after he sustained another calf strain
The centre-back is set to miss Tuesday evening's trip to QPR after suffering a fresh injury blow and will be absent for three weeks in total.
Platt feels that City must get to the bottom of the issue in order to avoid being forced to cope without their skipper.
"It is a concern that it's not a fresh injury," he told reporters.
|10/3||QPR are 10/3 with Bet365 to score over 1.5 goals against Manchester City|
"And it has happened on a couple of occasions but the concern is to make sure we clear up the problem."
Kompany has made 198 appearances for City in all competitions since signing from Hamburg in the summer of 2008.