CARLTON remains unsure when captain Marc Murphy will return from a right ankle injury. 

Murphy was hurt in the round 10 win against Geelong but hasn't been on the field since. 

The skipper has consistently been listed as being two or three weeks away since he was originally hurt.

"It's one of those syndesmosis ankles that can vary. It's really difficult to give you an exact timeline on it," coach Brendon Bolton said on Friday. 

"We'd love to be able to put an exact timeline on every injury, but with some of them, and that type of ankle injury, you can't. It just depends how it responds." 

However, Bolton was adamant there was no thought of sitting Murphy out the rest of the season. 

The Blues face Adelaide at the MCG on Sunday afternoon. The Crows sit fifth on the ladder and are arguably the form side of the competition, having won six games in a row. 

Dennis Armfield could make his return from a testicle injury, depending on how he trains on Friday and Saturday. 

"We play on Sunday, so we've got to get through another assessment on how he's travelling," Bolton said. 

While the Blues have surpassed pre-season expectations to post six victories from 14 matches, the coach identified ball movement as a key area for improvement. 

"We turn some balls over going forward, (and) made some decisions not in line with the way we want to play," he said.

Carlton is the second-lowest scoring side in the competition, ahead of only Essendon. 

Bolton expressed hope some of last year's draftees could push their way into the senior team.

"It would be great to see some of our draft class from last year," he said.

"But again … they need to earn that right."

Of last year’s Carlton selections, only Harry McKay (No. 10) and David Cuningham (No. 23) are still to debut.

No.1 pick Jacob Weitering has established himself in the backline and notched 12 matches. A stress fracture in tall forward McKay's back had him on the sidelines until a fortnight ago, when he lined up in the VFL seconds. 

Glandular fever struck midfielder Charlie Curnow, although he strung four games together earlier in the season.

Jack Silvagni made his debut against Collingwood last week while a hip injury has impacted Cuningham's campaign.

Senior defender Michael Jamison returns through the VFL this week after illness had him sit out, but Bolton was non-committal about when the 30-year-old would return to Carlton's line-up.

"It's hard to say. It just depends on form and how he goes," Bolton said.

"He needs some consistency in terms of playing at the level, and also his form needs to warrant it." 

Jamison is contracted until the end of 2017 but has managed just five games this season.