Essendon made the decision to pull former captain Dyson Heppell (14 disposals at 71 per cent) from the game as the tactical substitute in the third term, replacing him with the run of Matt Guelfi.

Coach Brad Scott said it was to give the 30-year-old Heppell the best chance of being ready for St Kilda off a six-day break.

"We wanted to get Guelfi into the game, and we wanted to play him on the wing. It was a line-ball call between two or three players," Scott said.

"To be perfectly honest, when it's line-ball, we really want to manage Dyson through this year and make sure he's at his best. So it fell that way, but I'm sure it shocked him, I doubt he's ever been subbed off in his life.

"You never telegraph a sub, either, so it was probably a surprise to him. I haven't spoken to him about it yet, but he's as team-oriented as I've seen anyone. He'll just play his part. Hopefully he watched Richmond play Adelaide and saw Dustin Martin get subbed off too.

"He played every game last season, which is a credit to him, but it's a long season and we want him at his best. So we'll just monitor him, and as soon as he shows some signs of fatigue setting in, we'll rest him and bring him back in so he's got every chance of playing his best footy.

"Out of a 23-game season, hopefully plus post-season (finals), if he plays three quarters of those at a really high level, that'll be a really good result for us."

Scott praised the game of the versatile Kyle Langford, who booted five majors after being swung from his defensive position last week, covering the absence of noted goalkickers Peter Wright, Sam Weideman, Jake Stringer and Anthony McDonald-Tipungwuti.

"Dale Tapping, our forwards coach, has talked before about Kyle being a difficult match-up, and he's a bit of a 'Mr Fix-It' for us, he can play in all parts of the ground. He's played even in the ruck before, so he's a really versatile player," he said.

"We were keen to settle him down, he played a really important role for us last week, but it's a sign of his class and maturity that he's able to adjust his game and fit into a forward structure that we try to base around system, rather than personnel."

Scott said it looked like key defender Brandon Zerk-Thatcher has sustained a standard sprained ankle affecting the lateral ligament, rather than a more serious syndesmosis issue.