It’s been a methodical, slower approach this time for the former Giant – one that he believes is paying dividends.
“I’ve made the eight month mark and it’s feeling much better now compared to the first one,” Ahern told NMFC.com.au.
“Definitely comparing seven months to the last seven months there’s a noticeable change.
“I’m feeling a lot stronger in the gym and running wise it’s feeling pretty strong.”
The first major milestone was straight line running, which Ahern ticked off at the 14-week mark.
“Then I had to tick off getting the muscle bulk back around my quads and comparing that to my right leg,” Ahern continued.
“Then also getting my hamstring strength back because that was a bit lower on my right side from my first hamstring graft, so I had to make sure that was where it needed to be.
“It’s a lot of squat work, leg press in the gym, and all that type of work helps the bulk come back a bit quicker.”
It took time for Ahern to progress from straight line running to the next step in his rehab.
“Once I got the all clear to start running I started doing a few Alter-G (anti-gravity treadmill) sessions, ticked a couple of them off and started to progress on-ground with straight line running for probably about two or three months until I really started to do a bit of change of direction stuff.
“I started doing change of direction about five months in but that was at walking pace, whereas when I started to do the running (change of direction) that was probably about the six month mark.”
Building confidence in his knee has Ahern optimistic he can take a major stride in the near future.
At this stage he’s hoping to join in with the main group for core skills in six to eight weeks, which he’ll then – all things going to plan – continue for the rest of the season.
When compared to his first torn ACL, the slower rehab pace this time has given Ahern peace of mind.
“I’ll make sure I can finish off this season having ticked off everything so I’m ready to go for the first day of pre-season,” he added.
“It’s good knowing that I don’t need to rush back for a game this year, so if I have little setbacks here and there I don’t have to stress about trying to get back quickly which is probably a good thing, being a bit more cautious.
“It gives me a bit more time to work on stuff that I need to do in the gym and also skill-wise on the track.”
The 20-year-old is set to return to football in 2018.