Walker has only recently resumed running, having carried a painful knee through several weeks before his 2014 campaign was cut short in July last year.

He has not taken part in the Blues' pre-season camp at Mount Buller and in Mansfield but has been training at the club.

Blues' director of coaching Rob Wiley said Walker's natural fitness would help him regain touch.

"He has just been a little bit slow, but he is back running now and it's just a matter of monitoring him and maintaining a smart way of training. It will be like a new recruit coming in, having missed a fair part of last year," Wiley said on Thursday.

"The good thing about Andrew is he is a very fit young man. He has got that ability to come through with his athleticism. He will fit back in nicely."

Walker managed just 14 matches last season, having been runner-up in the best and fairest in 2013.

The Blues open their NAB Challenge campaign against the West Coast Eagles in Mandurah on February 27 and then play Collingwood (March 15) and Geelong (March 22).

"We are hoping he [Walker] will be right for the last couple of games so ... it will be a matter of playing quite a few [players] so we have good numbers to choose from coming into round one."

The Blues held an intra-club match in Mansfield on Thursday, with emerging forward Levi Casboult particularly impressive. Casboult, who played 19 senior games last season, having managed just the 17 in his previous four years, was damaging up the ground and near the goals. His kicking, an area he has worked on diligently, was largely accurate.

"We have a number of players who have trained impressively. But Levi is certainly leading the pack. He had nearly a full year of AFL last year for the first time," Wiley said.

"He would have learnt a lot. He has come on in leaps and bounds."

Casboult worked alongside Liam Jones, the former Western Bulldogs forward determined to reignite his career.

Jones spent the early stages of the off-season working with former Dogs teammate James Mulligan, now a personal trainer, and has had coach Mick Malthouse help him adjust his marking technique. At 198 centimetres, Jones has the height to be an important option.

"He [Malthouse] just feels I can be in the contest and hopefully mark more balls if I can change my approach to jumping for the ball. So far, it's helped out. It's taken a bit to break bad habits," Jones said.

"[I am] just trying to get a bit more up [vertically when marking], less forward, trying to keep my feet after the contest rather than going to ground - losing my feet."

Jones played only 10 matches with the Bulldogs last season, returning 12 goals, leaving the former second-round pick in 2008 with 66 matches (68 goals).

"Liam has come with a lot of potential. He needs now to put it consistently week in, week out, and we believe if we get that dynamic and structure right up forward, then we can pose a lot of problems for opposition sides," Wiley said.

Patrick Cripps (ankle), Chris Yarran (calf) and Kade Simpson (ankle) were on light duties on Wednesday, joining Chris Judd and Troy Menzel.

"Crippsy rolled his ankle but he will back up doing stuff next week," Wiley said.

"There are all different forms of training you can do these days off legs. But as the intensity increases at this time of year, you are going to get a few of those (niggles) - that is the nature of the game."