CARLTON remains uncertain whether it will retain free agent Levi Casboult in 2018, with coach Brendon Bolton admitting the Blues will have to wait to see what unfolds.

The uncontracted Blue has been linked to Richmond for most of the season, and is understood to be on the radar of several clubs on the look-out for a big marking forward.

The 27-year-old leads the competition for contested marks with 48, and has lifted his goalkicking accuracy above 60 per cent in 2017, kicking 28 goals.

However, he missed a vital set shot against Essendon last Saturday when the game was in the balance, and his value remains a point of contention.

On Friday, Bolton was non-committal when asked how confident he was that Casboult would be at the club next season.

"We'll see how all that unfolds, I'd like to think so, but it always the unknown," Bolton said.

Casboult's kicking has improved this season under the tutelage of former Collingwood and North Melbourne goalkicker Saverio Rocca.

Bolton praised Casboult for the effort to put in, and described him as "a Carlton person".

"He has been really invested in our footy club … he is working really hard on his game all year," Bolton said.  

"I think people can see that, so he is a valued member of our team."

The Blues flew to Perth on Friday to play West Coast on Saturday night searching for their first win since they defeated Gold Coast in round 13.

Apart from the 65-point loss to Geelong in round 19 when it looked tired, the biggest margin in Carlton's seven-game losing streak is 26 points.

Bolton said the club hoped to get back on the winner's list against the Eagles and upset the home team's fading finals chances.

"Teams positioned where we are always have a purpose of trying to disturb opposition runs into finals. That would always be part of the motivation," Bolton said.