Worst fears confirmed. 
http://www.cardiffcityfc.co.uk/page/NewsDetail/0,,10335~2924958,00.html
The Cardiff City medical team have this evening confirmed fears that the injury suffered by Nicky Maynard at Millwall on Tuesday night will see the striker out of action for a number of months.
"Nicky has a torn anterior cruciate ligament, an injury that requires surgery," Cardiff City Head of Performance Richard Collinge said this evening.
"He will remain under the care of a local orthopaedic specialist and the Cardiff City medical team, working through a substantial rehabilitation programme with the goal of returning to first team action when possible. Instances such as this can see varied recovery times and we will do everything to support and guide Nicky through the rehabilitation process. The player has the backing of all of us at the club and we all wish him a speedy recovery, coming back stronger than ever."
http://www.cardiffcityfc.co.uk/page/NewsDetail/0,,10335~2924958,00.html