Manchester United have been installed as narrow favourites to reach the Europa League final ahead of their semi-final clash with Athletic Bilbao, but bookmakers are split over how tight the two-legged tie could be.

Most major UK sportsbooks including Bet365, Paddy Power and William Hill have priced United around 8/13 to qualify, with Bilbao available at 11/8. The first-leg odds show even more caution, with Bilbao marginal favourites at home at 7/5 and United at 9/5 to win on the night.

United’s unpredictable form has led to caution among traders. Despite their higher profile and stronger squad on paper, they have struggled for consistency and remain vulnerable to high-pressing sides like Bilbao.

“The market reflects both the strength of United’s squad and the reality of their season,” a William Hill spokesperson told us. “They are favourites, but only just. There’s real belief in this Bilbao team.”

Athletic’s unbeaten run at home in European competition this season, coupled with their aggressive, fast-paced style, has made them one of the tournament’s standout stories. Punters looking for value have already begun backing the Spanish side, particularly for the first leg at San Mamés.

Bettors are also eyeing the draw across both legs, with odds of around 5/2 for a stalemate in either game. With both managers expected to be cautious early on, the tight nature of the betting market suggests the tie could hinge on one or two key moments.

For those backing United outright, the best odds to qualify can still be found through smaller online bookmakers, though prices have been tightening. Several firms have also launched special promotions for new customers backing either side to qualify.

With the final in sight and very little between the teams in the market, this semi-final is shaping up to be one of the most tightly contested in recent Europa League history.