The 27-year-old scrum-half toured South Africa with the Lions this summer, earning a bench spot in all three Tests and coming on to the field during the stunning 28-9 triumph over the Springboks in Johannesburg.
But Ellis has since spent three months on the sidelines after suffering a reoccurrence of a knee injury in Leicester's Guinness Premiership clash with Newcastle on September 19.
The England international missed the majority of the 2007/08 season following knee surgery at the back end of Tigers' previous double-winning campaign.
That injury threatened to end his career prematurely and the latest setback has reminded medical staff at both club and country that Ellis will need to manage his knee differently over the next few years.
Leicester and England will therefore fit Ellis with a GPS tracking system to ensure he never trains more than the desired amount and doesn't put undue strain on his problematic knee.
"I did a lot of running in pre-season which had a detrimental effect on my knee and it has taken a while getting back," Ellis told the Daily Express after he made his long-awaited comeback in a reserve team match earlier this week.
"It's good to be back playing - the buzz is still there - but I will have to be a bit more selfish in the way I train from now on, instead of just throwing myself into everything.
"I will have to manage some of the on-feet stuff that I do. How far we run is monitored very closely in training with a GPS system that England use too, which is very useful for the conditioners.
"This is my ninth season as a professional and that is a lot of rugby, so I have to listen to what the conditioners around me say."
Ellis admits that the period that followed his latest injury has been a hard one to deal with.
The Leicester Academy product should have been on a real high this season following his return from South Africa with an enhanced reputation but instead he was forced to sit and watch as both England and Tigers attempted to plough on without him.
Time out reminded Ellis how short a playing career can be and that, despite still being in his mid-20s, it might be time to start thinking about the future.
"It was a tough period - it was an awesome experience with the Lions so it has been frustrating not to be able to carry that on - but I'm used to it. I've been there before with injuries, like a lot of players," added Ellis.
"There is no dodging the fact that it is a tough environment. We are looked after better these days with closer monitoring of our training and post-match screening, but being injured reminds you of what a privileged position you are in and how lucky we are.
"It made me think about what I will do after rugby. I hope to go into coaching when I finish playing and I'm doing as much as I can now. I'm working with Loughborough University and I'll soon be embarking on my level-three badge.
"You do become more aware of your age. I was playing alongside George Ford on Monday night who is 16," said Ellis.
"It is really strange how suddenly you change from being one of the young ones in the squad as players retire and move on.
"Time just flies, so we have to enjoy this while we can."