Evans missed the entire RBS 6 Nations campaign after receiving a 12-week ban for stamping on Leinster second-row Mike McCarthy but he makes a timely return with his region looking to overhaul Ulster in the race for a top-four spot.
The Ospreys have an easier looking run-in than their Irish rivals, as they face Zebre and Connacht in their remaining regular season games, while Ulster have to play high-flying Leinster and Munster.
"This is a crucial game for us. If we want to extend our season beyond next weekend we know that we have to go to Parma and win, there are no ifs or buts about it," said Ospreys boss Steve Tandy.
"We've had a good week preparing for it, there is a positive mood in the group and everybody knows what's at stake over the next 10 days.
"Our fate isn't in our own hands, but we have to concentrate on doing what we need to do to ensure that if results elsewhere go our way we are able to take advantage. We need to put in a very professional performance against Zebre where everybody is fully prepared, knows their roles, and are clinical in everything they do."
Tandy has handed a PRO12 debut to Wales U20 prop Nicky Smith, who is highly-rated at the Liberty Stadium, while, at the other end of the scale, veteran Bristol-bound back-rower Ryan Jones could make his 150th appearance for the region from the bench.
The visitors will start as favourites at Stadio XXV Aprile with Zebre sitting at the foot of the table. But lock James King has warned his team-mates not to underestimate their hosts.
"They are a tough side at home and the league table probably doesn't do them justice" said King. "We know how strong their forward play and set-piece is so it's going to be a battle, but we have the confidence to go there and win.
"We have got European qualification already in the bag which is great because that's where this region wants to be playing and competing. But we also want to be fighting for silverware and trophies so we're desperate to get into the play-offs."