Lachlan Keeffe wants to be part of Collingwood's finals assault, declaring he'll be fit and raring to go come September.

The Collingwood defender returned to football three weeks ago in the VFL, after more than 12 months out of the game with a ruptured anterior cruciate ligament.

With just 14 AFL games to his name, Keeffe told AFL Media he has his sights on being a part of the first AFL finals campaign of his career.

"That's 100 per cent what I'm aiming for (finals)," Keeffe said.

"It's full steam ahead and my knee's 100 per cent at the moment. The sooner the better from my perspective."

The 23-year-old became the fourth Magpie to go down with a season-ending knee injury in May 2012, following teammates Brent Macaffer, Andrew Krakouer and Luke Ball.

After surgery, the 204cm Keeffe lost nearly 10kg and was "bedridden" for a two-week period.

He shadowed Ball during his rehabilitation process, picking up a few valuable tips along the way.

Along with the primary aim of mending his knee, Keeffe had a goal of adding extra size to his frame.

"I was probably exposed a little bit playing on your really big key forwards last year," Keeffe said.

"I saw it as a positive, in a way. That was a driving force for me through the early stages of the rehab."

Keeffe's playing weight last year was 97kg. He tipped the scales at 101kg when he returned three weeks ago.

He started his rehab at a low base, gradually increasing his training load based on his pain threshold and the "feel" of things.

"That was the hardest bit. The unknown of the reconstruction, itself, and how hard to push things," Keeffe said.

He ticked off little milestones off along the way. He ran "pain free" for the first time in January, started changing direction in the middle of February and overcame the jumping and landing stage in March.

He was ready to go, but wanted to put in a month of solid training to feel confident that his knee would not betray him.

He practiced twisting and turning and reprogrammed his knee to cope with the force of jumping and landing.

However, Keeffe knows the big test will be how he handles the increased intensity of games in the lead-up to pushing for senior selection.

"You kind of wonder well, 'Is it going to be like it was?' And even to this point now, it's doesn't feel the way it used to," Keeffe said.

"But I've still got the confidence in my knees to go out there and do what I need to do on the footy field because of the work I've put in over the 12 months."