Gombau's honest assessment comes after his Reds side were forced to withstand a late Wanderers barrage to come away from Pirtek Stadium with a 0-0 draw on Saturday night.
In a dour contest played on a heavy track, the Reds created the better chances but had to make do with a point after some wasteful finishing.
"When one team is in two competitions, everyone wants to play good to have chances to play," the Reds boss said.
"This is extra motivation for everybody and I don't expect they would be tired at any moment.
"I have this experience because I coached for three years with Kitchee in the AFC Cup and we had to play midweek and weekends.
"In that moment the team did better than before because everyone felt it's important to be in the team and everyone wanted to play."
It was one of the winger's final contributions as he was forced off soon after with concussion after an off-the-ball incident with Wanderers defender Adam D'Apuzzo.
D'Apuzzo, who had already been booked for an earlier challenge on Ferreira, avoided another caution and stayed on while the Portuguese flyer's match was done.
"It always the player that's injured that has to go off and the player that does the action stays on the field," a miffed Gombau said.
"But this is football and the referee thought it's not a yellow card.
"He (Ferreira) copped an elbow and after that he didn’t know where he was and what happened before and in that moment we took him out of the game.
"He can go and rest at home because he has family here in Sydney and I think it's nothing very difficult for him...but we didn’t want to take a risk."
