When Celtic manager Tony Mowbray awarded Scott Brown the captaincy, the 24-year-old admitted he was surprised as anyone. But the midfielder is eager to silence his critics when he leads Celtic out against their Glasgow rivals Rangers in today’s Old Firm clash at Ibrox.

With Stephen McManus out on loan to Middlesbrough and Gary Caldwell sold to Wigan, new star striker Robbie Keane was expected to take the armband, but it was Brown who received the nod.

"The manager called me into his office last month for a chat. I wasn't sure what it was for - I thought he was maybe going to ask my opinion on who should become captain,” revealed Brown.

"But he offered me the role and I didn't hesitate to accept. It's a great honour and I was proud to be asked.

"I know I'm only the stand-in skipper until Stephen comes back from Middlesbrough. However, as long as I'm captain I will give my all and do my best to help us win games.

"I will just play my normal game. I will make challenges the way I always do and it won't be in my head to calm down.

"It's possible some people want to see me fall flat on my face as Celtic captain. But that's not going to happen. It will be a big test for us all at Ibrox but we will try to win.

"We have experienced players and leaders in the team. I will say my piece in the huddle before kick-off and I know the whole group will be up for it.

"I don't want to get involved in any conversation about whether this is a must-win game or not. This is just another match. We'll see what happens and discuss it after the derby."

A win for Rangers will put them 10 points clear at the top with a game in hand and that would make Celtic’s title challenge all the more difficult.

Brown knows how important the game is and remains confident he can lead his side to victory against a strong Rangers side.

He said: "If we win this game then people will say it's great and we'll be back on top form.

"If we lose some will say it's the end of the world. We can't predict what will happen but I know Rangers will make it difficult.

"They have lots of good players. Kenny Miller always gives his all, Kris Boyd scores goals for fun while Steven Whittaker, Steve Davis and Kevin Thomson are all good in the midfield.

"But if you ask them about us I'm sure they will say we also have good players.

"We haven't beaten Rangers this season but we have played well against them. In the last game at Parkhead we scored first then they equalised against the run of play.

"We also had a goal disallowed when Marco Fortune went up for a challenge with Allan McGregor. We've been unlucky with a couple of decisions.

"But, to be fair, every team could say they've had a couple of decisions go against them. That's just the way it goes."