The versatile defender or midfielder is out of contract in the summer and has been a linked with a move to England.
His appearance against East Kilbride in the 2-0 Scottish Cup win earlier this month was his first in the starting line-up since sustaining a thigh injury in the home Europa League defeat by Ajax in September.
Consequently, the 29-year-old international star has kicked off only six of his side’s 42 matches during the current campaign. That record prompted Deila to declare last week that the player – who has turned out at centre-half, left-back and midfield – must prove his fitness before any talks will be held about extending his stay at the four-in-a-row champions.
He said: “Charlie is a top-class player and he’s just getting his fitness back. He played against East Kilbride recently and got 70-odd minutes under his belt.
‘It was good to have him back on the pitch because he’s a character. It’s great to have new faces and it’s almost like having one with him.
“Don’t forget that he was Scotland’s Player of the Year a few years ago and it’s been a big loss for us not having him in the squad for the last three or four months.
“Charlie’s a big-game player, as well. He always turns up on the big occasions and that left foot of his is a wand.”
Brown contended that it would make no sense for the club to lose a player who has been capped 20 times by ex-boss Craig Levein and current gaffer Gordon Strachan.
The midfielder added: “He was out for a while and then he came back and hurt the same thigh again.
“He loves the club. He was born a die-hard fan and he still is one and you need guys like that in the dressing room because they bring a lot to the club and the fans like that. Charlie knows what it’s all about and he lives for this club.
We have reduced the price of a selection of our Celtic books on CQNBookstore.com
The Winds of Change and Caesar & The Assassin are reduced to £13.99 each, Seville The Celtic Movement and The Quality Street Gang are now only £9.99 each. The Jock Stein book, Willie Wallace & Tommy Gemmell’s books are all just £6.99 each.
Order ANY book or DVD and we’ll send you a copy of the 2015 CQN Annual absolutely free and we will add a wee dram for you to enjoy when you’re reading!
We also have the Neilly Mochan book and DVD from Paul Dykes available and much more.
Order now at www.CQNBookstore.com