The Sunderland striker sustained a groin injury in training today, adding to England manager Fabio Capello's injury problems ahead of the Wembley match.

Capello told a press conference televised by Sky Sports News: "Darren Bent is out - I think we will play Peter Crouch."

Central defenders John Terry and Phil Jagielka have already withdrawn from the squad because of injury, although Rio Ferdinand is back in the side - and will regain the captain's armband from Steven Gerrard.

Capello continued: "I spoke with Steven yesterday evening and explained why Rio will be captain against Montenegro. He understood everything - he knows the rules. I have also told the players that Rio would be captain.

"I decided when I started as England manager who will be the captain and the vice-captain. The players understand why Rio is the captain, and after him Steve Gerrard, and after Gerrard another one.

"When I spoke with Steven I told him, 'you were a fantastic captain and you have to play like a captain tomorrow.'"

Capello is confident Ferdinand's knee problems are behind him, adding: "I have monitored him - he is fit completely. Also I watched the game against Valencia. I think now he's 100% fit.

"There is no problem about Rio's injuries. He's really good when he plays.

"He's really important for the other players, he speaks a lot during the game. It's really important for me, I prefer this kind of player on the pitch."

The Italian did not feel the need to call up another central defender following Terry's withdrawal, adding: "I've worked with the back four and I have big confidence in these players. The ones who are here are good at the moment.

"Hopefully we will play in the same style as we did against Switzerland."

Ferdinand admitted to having doubts as to whether he would regain the armband.

He explained: "I didn't know if I was going to be captain or not - I was more concerned about being in the squad and being fit... it's been a fair road back.

"The manager is always analysing you physically and mentally and you've got to perform. He has seen me as the right person and I'm delighted with that - but if it had gone the other way I would have shaken Steven's hand and said 'good luck to you' - that's the way it is.

"It's a great honour to be named England captain and it's great to be playing again. To come back now and be named captain is fantastic but Steven has done a fantastic job, especially in both European Championship qualifying games - we've won both games quite convincingly.

"We've got a number of leaders in this squad - and the more there are the better we will be as a team.

"Steven and Wazza (Wayne Rooney) have worn the armband before so we've got players with experience who know their way around the pitch. If we can continue as we have started in this group we'll be on the right road."

The Manchester United defender admitted missing the World Cup because of injury was "a disaster".

"The first 48 hours when I got the injury were the worst in terms of thinking of the consequences and analysing it. Missing the World Cup was a disaster for me but you've got to wipe yourself down and get on with it.

"I worked hard on rehabilitation and at the training ground at Manchester United. The staff have been fantastic helping me get to this point."

Ferdinand is hoping England's problems with injured central defenders does not continue.

He explained: "I'm pleased to be back and fit but there have been many injuries in this department.

"It's hard for the manager, not having the continuity, so fingers-crossed we are over that period, we can get people back to full fitness and the manager can have a full squad to pick from."

On training this morning Ferdinand continued: "There are a few fresh faces - it's nice to train alongside Jack Wilshere and Adam Johnson, young hungry boys who are talented and trying to get in the team.

"It makes you feel a bit older but it's a good ambience and long may it continue."

On the fact Ferdinand is one of only three fit central defenders in Capello's squad, he joked: "I think the manager will have someone sitting with us all afternoon and evening, making sure we don't get injured."

The defender knows all about Montenegro front man Mirko Vucinic, who has celebrated goals by removing his shorts and putting them on his head.

Ferdinand said: "I know him from when we (Manchester United) have played Roma. You get booked for something like that in our country so it's not something we'll be following suit with,

"I knew they would be one of stand-out teams in the group. It will be a hard game and we've got to make sure we bring our 'A' game to make sure we put it to bed because they've started very well in the group."