Shamrock Rovers need to be willing to employ the "dark arts" away at Víkingur Reykjavík on Tuesday in order to have the best chance of progressing to the second qualifying round of the Champions League, according to Keith Treacy.
For the second season in a row, the Hoops' opponents in Europe's elite club competition are reigning Icelandic champions.
Last year they fell foul of an impressive Breidablik side. This time round, they will meet a Vikingur team who are top of the Icelandic top flight and six points ahead of Breidablik, with the first leg in Reykjavík on Tuesday night and the return at Tallaght Stadium coming next week.
Progressing to the next stage in the Champions League would allow Rovers to enter the Europa League and Conference League qualifiers at a later round should they eventually drop out of the leading competition.
It's a pathway that played a part in allowing the Dublin club to qualify for the Conference League group stages in the 2022-23 season.
But to do so by overcoming Vikingur over two legs would require Stephen Bradley's side to compromise on their footballing principles.
That is the view of former Republic of Ireland and St Patrick's Athletic winger Treacy as he told this week's RTÉ Soccer Podcast.
"(Vikingur) are obviously a very good team. You've mentioned they've drew with and beat Breidablik. They seem to be a level up and are top of the league," he said.
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"The one thing I want to see from Shamrock Rovers is the opposite of what I've seen the last couple of years.
"It needs to be said, I get the merit from Stephen Bradley, from a coaching point of view, from a managing point of view, wanting to play the same way they play in the League of Ireland.
"But then you come up against really good opposition - we know they're good opposition because (Rovers have) played people of a similar level and fell short against them - so Shamrock Rovers need to go to Iceland, I don't want to say shut up shop, but they have to have the dark arts.
"They have to be able to slow the game down, they have to make it disinteresting. They don't have to go there and score but they have to restrict (Vikingur), they have to make it really, really ugly."
The ultimate goal would be to ensure that Vikingur do not come to Tallaght with any significant advantage, he added, before employing a more aggressive high-tempo approach at home.
"If they come back with a 1-0 defeat, all of a sudden the game has changed, it's a different game," Treacy said.
"Reykjavík come over here thinking, 'These are so standoffish, they don't want to press us', then they go Tallaght and it's a different kettle of fish.
"The tempo is up, everything is a 100 miles an hour. But the hard work and suffering has to be done in the first game.
"It's a clean sheet or one at the most that you can allow in. Other than that, the tie is still in the balance.
"And if you can go over there and nick a goal, I'm sure that's what Shamrock Rovers fans and Stephen Bradley will be saying to me.
"But for me, they've done that, they've tried that, they've opened up, they've made silly mistakes and whereas this season they have been getting punished in the league, but generally over the last couple of seasons they've been getting away with it (domestically) but in Europe they were getting punished.
"This is Champions League football, this is big stuff, so any mistake will be punished. Minimise your mistakes, play in the opposition half. If you want (Vikingur) to have the ball, let them have the ball but be defensively sound. And set pieces will be a big thing, if they can nick something over there, no problem.
"But bring it back to Tallaght with the tie still in the balance."
Watch every game from Euro 2024 on RTÉ2 and RTÉ Player as well as highlights and goals as they happen on RTÉ Sport digital platforms.
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