Braga beat Spartak Moscow in the play-off before topping Group K undefeated, finishing a point above Wolves.

They lie eighth in Portugal's top tier but their domestic form is misleading, according to compatriot Mendes.

"In the group, Braga were by far the best team against strong opponents," the former Ibrox midfielder said.

"They're not doing so well domestically, dropping points where they shouldn't. But in the Europa League they are playing brilliantly.

"The most important thing about this team is the dynamic they have on the field - the movement, the pace, the way they keep the ball. In the Europa League they have been doing that very well.

"It's a team that in the past year is playing fantastic, they have great players and Rangers should be careful."

Rangers qualified behind Porto in Group G, having beaten the Portuguese 2-0 at Ibrox after a 1-1 away draw.

Former Portugal international Mendes, who won the 2009 league title during his two-year Ibrox spell, was impressed by those performances from Steven Gerrard's side, but maintains Braga will present a different and formidable challenge.

"It's a hard one," the 40-year-old added. "I saw both games against Porto and was really surprised with the way Rangers played. They played really well.

"Braga approach the game in a different way, they are more technical than Porto, so I'm not sure how Rangers will deal with it. Rangers will need to chase and in parts of the game must boss it."