NATHAN Buckley's decision to bench skipper Scott Pendlebury during a crucial period of Collingwood's loss to St Kilda has been lashed by Geelong premiership captain Cameron Ling.

The Magpies captain spent 14 minutes of the third quarter on the bench when the 10th-placed Saints kicked four goals to two on the way to a 9.15 (69) to 7.13 (55) victory.

It raises more questions over Buckley's coaching as the Magpies, aiming to make their first finals since 2013, sunk to a 1-3 win-loss record on Sunday.

Gun midfielder Pendlebury, who had 15 touches by half-time and 25 for the match, had no injury issues when rested in the third quarter, prompting former Cats star Ling to take aim at Buckley.

"Can I say if there wasn't an injury to Scott Pendlebury ... I can't believe that he's sat 14 minutes on the bench in the third quarter in a game that was there to be won," Ling told 3AW.

"That is unbelievable. The bloke's a star. Get him on the ground. You've got to have your captain and your superstar on the ground ... unless he is injured.

"That's the coach Nathan Buckley (who makes the decision). All the bloody sports scientists gone made ... you've got to win the game."

A frustrated Buckley said post-game the 29-year-old Pendlebury "probably wasn't as sharp" as he had been in previous games.

But he denied that the captain was carrying an injury, or that he had been benched due to form, and said the move was part of "normal rotations".

"We put a lot of emphasis on our leaders and we ask a lot of them," Buckley said.

"If you're going to be a leader in this caper, you've got to keep buttering up and backing up.

"Pendles, more often than not, he brings the right intent and energy. He was probably a little bit quieter tonight."

The loss leaves the Mapgies in 13th place after previous defeats to Western Bulldogs and Richmond before an impressive victory over Sydney in round three.

Collingwood next face Essendon in an Anzac Day MCG blockbuster on April 25