PROMISING young Kangaroo Jesse Smith is out for the season after suffering another hamstring injury, coach Dean Laidley has confirmed.

Smith, 21, suffered a severe ankle injury a couple of years ago, then finished sixth in the 2007 NAB AFL Rising Star award before battling through the pre-season this year, but hamstrings have been the issue since then, courtesy of his curtailed build-up for the year.

Laidley said the club had only just made the decision to let Smith concentrate on getting right for next year, and said the youngster was finding the latest setback difficult to deal with.

"He's struggling with the mental side of it, he really is," Laidley said.

"He did his hamstring again on the weekend. It's got nothing to do with his ankle, his ankle's probably in the best shape it's been since he did the injury, which is a real bonus for us.

"He just hasn't had the strength in his legs, and his lack of conditioning with not training and playing the games he did last year, coming off a limited pre-season, even though he had a good year last year, and probably doing no pre-season (this year) – the strength in his legs and the confidence in his legs is just shot at the moment.

"We're just going to basically put him on a strength program, a running program – so he can do a little bit of a mini-pre-season now until we finish playing, then he can have his break and come back and hopefully be strong enough in his legs to get a thorough pre-season behind him and then play some games for us.

"He's very, very important for us."

Laidley said the fact that Smith's problems were caused by multiple injuries was a good sign.

"It hasn't been chronic – one injury. He certainly had a bad injury with his ankle, and then this year he's done two or three hamstrings, purely because of his lack of condition in his legs, and his ankle's been fine.

"If it was the same problem, yeah, we'd probably be concerned."