Adelaide defender Ricky Henderson is confident the Crows have the depth to cover the expected loss of teammate Matthew Jaensch who appeared to seriously injure his knee against St Kilda on Saturday.

Jaensch will have scans on Monday but the club expects to be told he has ruptured his ACL, which would likely rule him out for a year.

His left knee gave way as he tried to change direction in the third quarter against the Saints at Adelaide Oval, leaving him in clear and considerable pain clutching at the front of the knee.

Crows coach Phil Walsh said the side was able to absorb Jaensch's absence by switching players around – David Mackay was used as a defender once Jaensch had been stretchered off.

Henderson – who collected 23 disposals in his return from a strained pectoral muscle – told AFL.com.au there were also players looking for an opportunity in the SANFL, including draftee Harrison Wigg.

The small defender's reputation is built around a quiet work ethic that lends itself well to elite football.

His left foot is also superb.

Wigg managed 14 possessions against Port Adelaide in the SANFL on Sunday afternoon and finished with a team-high six rebound 50s.

"We've got a few boys running around in the SANFL playing some alright footy – Harrison Wigg's been playing really well," Henderson said.

"If the opportunity does pop up he's probably a bloke who could slot in.

"He works really hard, he's actually a really quiet bloke, he just goes about his work.

"Hopefully he gets rewarded soon because he's been playing some really consistent footy."

But Wigg's AFL debut might have to wait a few more weeks.

Although happy with his development, Walsh said he wasn't quite ready to break into the senior side.

Instead, the coach suggested Mackay would spend more time in defence as he did towards the end of Saturday's win over St Kilda.

Fellow midfielder Richard Douglas has previously told AFL.com.au he was eyeing more time in defense, but he remains about a month away with a foot injury.

Sam Kerridge was again strong in the SANFL with 23 disposals, eight clearances and a goal and could be inserted to cover Mackay's absence in the midfield if he is moved back.

Riley Knight (25 possessions) made a terrific return from an ankle injury alongside Wigg and Kerridge on Sunday, while veteran utility James Podsiadly (19 possessions, five rebound 50s) also got through his return from a fractured back.