With the tie evenly balanced, securing a third round meeting with Belgian giants Anderlecht is the goal. Ekranas, unbeaten at home in their last five European games, will be quietly confident having secured a 0-0 draw in the first leg at Tallaght Stadium last week.
But Powell is adamant Rovers have nothing to fear.
“It’s definitely a winnable tie for us,” said the 24-year-old left-back. “Obviously, we’ve played them at home and know what they’re about.
“It was disappointing not to score at home, but keeping a clean sheet was massive for us. We’ve to come here, score a goal, go at them. We won’t be fearing them.
“It could be a defining game in our season. We’ve just got to concentrate on the game. And, as I said, we fancy our chances.”
Given their poor results, pressure has slowly mounted on Stephen Kenny, but Powell stresses the dressing room is backing their manager.
“All the players are fully behind him,” said Powell. “We’re all pulling in one direction. We’re all here to do well and win things.’’
Kenny, meanwhile, says he accepts he’s coming under mounting pressure as fans once again chanted for him to go after Friday’s 0-0 home draw with Bray Wanderers.
“I’m not foolish. I know we need to win games,” said Kenny.
“Am I under pressure? Most likely I am. I think that’s the reality. There is no point in dressing it up any other way. The main thing is this is a results business, I do know that. We have to go and try to win out here. We believe we can win and get through.”
Captain Ken Oman will be given every chance to prove his fitness after coming off against Bray having aggravated a dead leg. If he doesn’t make it, Colin Hawkins will partner Craig Sives in central defence.
Stephen O’Donnell didn’t travel due to a knee injury while fellow midfielder Stephen Rice is nursing a slight ankle knock, but expects to be passed fit.
Gary Twigg returns in attack as he bids to score for the first time in 17 European games.
SHAMROCK ROVERS (probable): Jansson; Sullivan, Sives, Oman, Powell; Rice, Brennan; Kavanagh, Finn, McCabe; Twigg.