Richard Foster accepts Rangers' chances of retaining the SPL title will be badly hit if Kenny Miller accepts the offer of a move to Birmingham.
The 31-year-old is out of contract at the end of the season and has so far failed to agree a new deal to remain at Ibrox.
Miller has already netted 22 goals for Rangers this term and Foster is well aware of how important he would be in the second half of the campaign if he were to remain in Glasgow.
"I think we've got a better chance of winning things with Kenny still here," said the on-loan Aberdeen full-back.
"I'm glad that decision is not mine to make and I'm sure whatever happens, the rest of us will just have to get on with it. But I would like him to stay.
"Everyone has seen what Kenny has brought this season with his goals but he brings more than that, he's a clever player and he brings other players into the game.
"Especially this season, he has been a massive player for Rangers."
Goalkeeper Allan McGregor has also been linked with a summer move south of the border and Foster knows his departure would mean the loss of another crucial member of the squad.
He added: "I don't think there is a better goalkeeper in Scotland than Allan McGregor, I don't think there is a better Scottish goalkeeper.
"These are big players and, if we want to win things, I think we need to keep hold of them."
Miller is now thinking over the personal terms offered by City before deciding whether or not to move to St Andrew's.
A statement from Rangers read: "Rangers can confirm the club has accepted a bid from Birmingham for Kenny Miller.
"The striker is now free to discuss personal terms with the Premiership side."