The City manager had just opened negotiations on a new deal for the China international, whose current contract runs out next summer.
But the utility player damaged his cruciate and medial ligaments in a challenge with Eidur Gudjohnsen towards the end of the first half against Chelsea on Saturday, and is likely to be sidelined until the end of his present deal.
Jihai Sun, 27, will therefore not have another chance to convince the City board he is worthy of a contract extension.
However, given his recent form - again on Saturday as a stand-in central-midfielder until his injury blow - Keegan is in no doubt.
"What I would like to do is say to Jihai that we will sit down and put something there," Keegan told M.E.N. Sport.
"I will have to talk to the board. At the moment it is a difficult club financially but I would like to think that as a club we would do the right thing.
"He has hurt himself playing for us and we should be looking to offer him something. We are not a charity but we shouldn't underestimate Jihai's contribution to the club. We'll have to see how big the heart of the board is."
Blues chairman John Wardle added: "I will be having detailed discussions with Kevin and our medical staff before the matter goes before the board."