Interim boss Rini Coolen accepts Rosenborg will have to take risks if they are to rescue their Champions League hopes against Celtic on Wednesday.

The Hoops are 3-1 up from the first leg of the second qualifying round clash at Parkhead last week, when the scoreline flattered the visitors.

Coolen, who took the reins just before the trip to Glasgow after Rosenborg dispensed with the services of boss Kare Ingebrigtsen, conceded that his side will have to gamble if they are to upset the odds and secure a meeting with AEK Athens in the next round.

Read more: John Hartson: Celtic need to keep their wits about them to finish off Rosenborg

"Celtic deserved the win last week and in the end we were lucky that we didn't lose more goals," he told Press Association Sport ahead of the return game in Norway.

"But hopefully we can do some things differently tomorrow. We are playing at home and we have our supporters.

"We have a chance to win the game but we have to create those circumstances and yes we have to take some risks and yes we have to give away some spaces, but we will not open the door.

"We know things happen in football that you don't expect. We have examples in high-level games, Champions League qualification games and in the World Cup.

"Anything can happen in football. Sometimes things happen that you don't expect but realistically, it will not be easy.

"Celtic have a bigger chance to go through than us but it doesn't mean that we don't have a chance at all."

Skipper Mike Jensen does not have to look too far back for reasons to be hopeful.

After the Norwegian side were knocked out of the penultimate Champions League qualifier last season by Celtic, they were paired with Ajax in their Europa League play-off and beat the previous season's finalists 1-0 in Amsterdam and 3-2 in Trondheim.

Read more: John Hartson: Celtic need to keep their wits about them to finish off Rosenborg

The 30-year-old Denmark midfielder told Press Association Sport: "After we lost to Celtic last year we beat Ajax home and away.

"We were at our best then. It is always small margins and some luck and sometimes you need that.

"It is football, anything can happen and you have to believe in yourself.

"Celtic are big favourites to go through but it is not like we have zero chance.

"It is difficult to put our chances into a percentage but if we play at our best we are a really good team and we have shown that a lot of times.

"But we have to step up from the game we played at Celtic Park."