Nani, who injured his foot last weekend, returned to training late in the week and will now face a late fitness test to determine whether he will be available to start against Die Mannschaft in L'viv.
"We will assess his condition," said Bento. "He was out for some time and he has had similar injuries before.
"If he does not start, that will not change who we are as a team. We will seek a good result from the first minute."
Nani made 29 appearances for Manchester United this season.