St Kilda skipper Nick Riewoldt has suffered a fresh calf injury and is likely to spend another week on the sidelines.

Scans on Saturday confirmed a low-grade calf strain for Riewoldt, who was a last-minute scratching from Friday night’s AFL clash at the MCG.

The club is yet to rule Riewoldt out of contention for Saturday’s game against Carlton in Wellington.

But coach Alan Richardson conceded the trans-Tasman trip would hurt Riewoldt’s hopes of returning against the Blues.

“It’s not ideal. He’d have to be reasonably right, relatively early in the week (to play),” Richardson said after his side’s 74-point loss to Collingwood.

“It’s unlikely we’d chuck him on a plane if he’s 50-50 at best.

“We wouldn’t be doing the team any favours, we might have seen that tonight.”

Riewoldt was named for the Saints on Friday night.

The champion forward entered the MCG with every expectation he would play, despite a sore calf that prevented him doing much work on the track in the past week.

The 32-year-old was named on the final team sheet but a setback during the warm-up meant he couldn’t take part.

“He’ll have scans. If they’re clear he’ll be a chance to play, but he’s no certainty to play next week,” Richardson said.

No.1 draft pick Paddy McCartin made an underwhelming debut in place of Riewoldt, snaring three marks and failing to score.

Richardson admitted the key forward wasn’t quite ready for the top level.

“He struggled. It’s an awkward way to prepare … when you get told an hour before we play that you’re going to play your first game of footy,” he said.

“But he’s a competitive kid … he got going.

“In an ideal world he wouldn’t have played. He’s probably not quite ready, but we thought his last quarter was reasonably positive.”