Jenkins has not played since seriously damaging his knee in the closing seconds of a man-of-the-match display in Wales’ win over South Africa in November 2018.
The 27-year-old has had three operations since then and suffered several setbacks during his recovery, but is now ready to get back on the field.
“We don’t want to put too much pressure on Ellis, as you can imagine,” said Blues director of rugby Dai Young.
“Everybody has been really eager to see him back on the field and it’s fantastic that he’s going to have a run-out on Friday.
“Obviously, we have got to look after him as well. He’s probably only going to play 40 minutes because that’s the right thing to do.
“But he’s been in full training now for a couple of weeks and he’s getting better with every session.”
As for what he’s looking for from Jenkins, Young said: “For him to come off all intact is the first thing and with a smile on his face. I think that’s huge.
“Being out injured is never a nice place to be and when you’ve been out for as long as Ellis has, I am sure he has had some dark moments which he has had to come through.
“He’s going to be nervous and really eager to get out there.
“I am sure he is looking forward to his first carry, his first tackle and his first jackal.
“It’s just great to see him back in the game and it would be lovely to see him come off with a smile on his face.
“He’s been a big part of the fabric of the Blues for a number of seasons and somebody any team would miss.
“He’s not only a good player but a real good leader on and off the field, with his professionalism.
“He really is important to this set-up and hopefully it will go well for him.
“I won’t be putting too much pressure on him. I don’t expect him to be Ellis Jenkins the international straight away.
“We just need to support him back to his best.
“He is at a point where he has come through the dark days and it’s a lot brighter for him.
“I am just really pleased we are only a couple of days away from him actually getting out on that park.
“It’s been a long time and a lot of hard work has gone in to get him to where he is now.”
Young added: “We are planning to start him and give him 40 minutes.
“I know through past experience, if you have been out injured for a while being on the bench is a bit more nerve-racking.
“You just want to go through the warm-up and get out on the pitch.
“We are looking to give him the first half pretty much. If that goes well, I am sure he will be nagging to have a bit more time, but we’ve got to protect him from himself a little bit.
“He was quite happy to put himself forward to play against the Scarlets the other week, but I felt he needed a little bit more time in training.”
Wales wing Owen Lane will also make his comeback from injury versus the Ospreys, having not played since November.
Meanwhile, the Blues have seen three players called up to the Wales Six Nations squad in James Botham, Lloyd Williams and the uncapped Willis Halaholo.
“It’s a big part of your job to try and produce players for the national set-up,” said Young.
“It obviously tests us as a squad but it’s certainly something we welcome and they go with our best wishes.”
