Skipper Scott Brown believes Salzburg are not only the toughest team Celtic have faced this season but also the fittest.

A win over the already-qualified Austrian side in their Europa League Group D clash at Parkhead tonight will see Ronny Deila's side also book their place in the last 32 of the competition with one game remaining, as will a draw or defeat if Dinamo Zagreb fail to win at Astra.

However, Brown was impressed by Salzburg in the section opener in September when the home side battled back after going behind twice to the Hoops – with the Scotland captain scoring the second – to grab a merited 2-2 draw.

Salzburg won their next three fixtures to take them on to 10 points, two clear of Celtic although Brown, who returns after missing the 2-1 home Premiership win over Dundee on Saturday though suspension, does not think that will affect the visitors’ attitude.

“I don’t think it’s going to matter to them that they have qualified because they are a great team,” he said, before being asked if asked if he felt Adolf Hutter’s side are the toughest Celtic have faced this season.

“Yeah, definitely, I think they are the fittest as well,” he said.

“It was a hard game when we played them over there but we managed to get a point and I think it shows you how well we’re doing in this competition.”