His recovery and rehabilitation period proved problematic with three operations required on it last year, and it was not until last November that Ferris admittedly 'felt no pain in the ankle for the first time in 12 months'.
It has certainly been a long road back for the 28-year-old forward - with 'so many stumbling blocks' along the way - but back-to-back appearances for Ulster show he is making good progress.
It is a welcome development for a player who has had to cope with a catalogue of injuries over the years - hand, back, hip, calf, shoulder and knee (he has a modified training regime due to the removal of cartilage and the ligament damage sustained in his left knee).
He had a 17-minute cameo against the Scarlets at Ravenhill last weekend, including this memorable driving tackle on Kristian Phillips, and played the entire first half of Ulster's 9-3 victory over Edinburgh.
Speaking to BBC Sport after the Edinburgh game, Ferris said: "It's tough coming over here to Murrayfield, the pitch has been pretty heavy. We knew the conditions were going to be tough as soon as we woke up this morning.
"We just dug in there, we knew it wasn't going to be an open game for either team.
"From a personal point of view it went really well. Last week (against the Scarlets) it was a little bit more open, the ball was being thrown around.
"But it's nice to do a few hard yards, especially on a big pitch like Murrayfield.
"The ankle was good. It doesn't really play on my mind when I'm out there playing. It gets a bit sore afterwards, but we just kinda manage that during the week in my training load.
"It's another 40 minutes and you just try and keep building on that. Fingers crossed in the next couple of weeks I'll build back up to 80 (minutes)."
The Ireland and Lions flanker is proceeding with caution as he hopes to feature for the province in their upcoming Heineken Cup quarter-final clash with Saracens on Saturday, April 5.
"Obviously there were a few ups and downs along the way (with my rehabilitation), but I suppose after the third operation on my ankle - to finally get it sorted out - it's been one way for me," he explained.
"I've been doing so much running that it was just about taking the pitch, and I got to do that last week in front of my own fans.
"I'm not sure what the situation will be next week with Cardiff playing on a 4G pitch, but it would be good to maybe get another half an hour off the bench or something like that to give myself a chance (to play against Saracens).
"Playing for 20 minutes or 40 minutes - especially in weather like that - it's tough to get momentum and kinda get the ball rolling for myself.
"It's tough to find form, especially when I've been out for so long. I've just got to stick my hand up for selection when the time comes.
"We know the next few weeks is building up to Saracens and another win will just keep the ball rolling."
Asked about how close he is to full fitness, he admitted: "I'd say I'm a good bit off. The running is not an issue, it's taking the impact - smashing into mauls and rucks, that's the tough bit.
"It's about gaining that match fitness. 20 minutes last week and 40 minutes here, they're good stepping stones.
"But I'm definitely not out of the woods, people have got to understand that just because I'm back playing rugby doesn't mean I'm 100% fit and ready to go.
"It's all about the rehabilitation process and trying to build back up to that 80-minute performance."
Ferris is looking forward to linking up with some of Ireland's Six Nations winners - the likes of Rory Best and Andrew Trimble - as they return to training next week ahead of a crucial period of the season for the Ulstermen.
As Mark Anscombe's side step up their challenge for league and European honours, the powerful back rower insisted: "I just want to try and get a bit of form and get involved as much as I can.
"It's great being back in. We've Rory Best and Andrew Trimble back in next week, Tommy Bowe is coming back, Luke Marshall, Paddy Jackson...guys coming back in that are just going to bolster the squad.
"Nick Williams came off the bench there tonight, putting pressure on me. You've Robbie Diack who is playing very well. It's a great place to be, we've only lost two games out of the last 17 or 18.
"We're definitely the in-form team in Europe. It might not have shown out there tonight but we still got the four points."