The 2012-13 runners-up - who are contesting their third semi-final tie in four years - will play Serie A leaders Juventus in this year's last four, following Friday's draw in Nyon.
Former Benfica forward Gomes, who now holds an advisory role at the club, feels Jorge Jesus' side have been presented with a particularly tricky obstacle.
"Maybe it was the strongest team among those possible, but the Spanish teams (Sevilla and Valencia) are also very strong on home turf," he is quoted as saying by A Bola. "The most important is to be in the semi-finals for the third time.
"It will be a difficult game but we have a 50 per cent chance.
"We will work to be present in the final.
"'The goal is to be on all fronts until the end and we will do everything to celebrate this year."
Juventus travel to Portugal for the first leg on April 24, with the return meeting taking place in Turin seven days later.
The winner will then face either Sevilla or Valencia in the final, which will be held at Juventus Stadium.
