Slaven Bilic thinks West Ham's Andy Carroll is unstoppable in the air

West Ham manager Slaven Bilic says that an in-form Andy Carroll is "almost impossible to mark".

The England striker has suffered terrible luck with injuries during his time at Upton Park but is now back in action following a long lay-off due to a knee injury.

Carroll has made three straight appearances from the bench and secured a 2-1 victory over Chelsea last Saturday with a brilliant header.

The Hammers are now up to third in the Premier League table but Bilic says he will continue to be careful with the club's record signing.

"At the beginning it was six weeks individual training, then for a couple of weeks he was training twice with us and then one day with the physio," said the Croatian manager.

"Now he is back. Okay, we are still a little bit cautious because of the injury that he had, but now we have to stop him from training. We have to tell him 'right, the last bit of the training you have to rest' because he loves football.

"I don't know him from the past but he is a lad that would like to play five-a-side or finishing or whatever.

"He loves to train and when he trains he goes in 100 per cent, so sometimes we have to stop him."

And Bilic says that, when firing on all cylinders, Carroll is without compare when it comes to aerial prowess.

"Now hopefully he is in a good position to become less injured or, if we are lucky, hopefully free of injuries," said Bilic.

"That was the main issue, that was the problem. His quality, as I said 20 times, was never an issue. When he is fit, he is capable of everything.

"We are good in the air without Carroll, we have Diafra Sakho and Nikica Jelavic, who are good in the air. But he is maybe the best in England - definitely, when he is fit.

"It is not just his ability. When a good ball comes in like Aaron Cresswell's against Chelsea it is basically up to him. No matter how good the defenders are in the air, it is more up to Andy.

"If the good balls come to an area where he is, it is almost impossible to mark him.

"His game is not just that. He has a sense and feeling for the game, he sees the move two or three moves before, which makes him a great player."

When asked if Carroll looks after himself well enough away from football, Bilic joked: "I don't live with him.

"Up to some point, I am not a policeman and I am not investigating their lives. They are young people, they are going out. We all used to go out.

"We had a few chats, he has matured enough. When you talk to him, he is like a proper man."

Carroll could make his first Premier League start since January when West Ham travel to Watford on Saturday, although Bilic may again prefer to unleash him from the bench.