Gloucester sweating on duo ahead of Gallagher Premiership play-off

Slater faces a fitness test later this week on a shoulder problem, while Thorley made his comeback from knee trouble during last Saturday's Premiership defeat against Sale Sharks but went off inside the first 20 minutes.

"Ollie is wait-and-see," Gloucester head coach Johan Ackermann said. "He can't train with us at the moment.

"We can't play somebody if he is not 100 per cent, and we will make a calculated decision later in the week.

"He is so explosive and fast and if the knee is not 100 per cent, it will influence his full-out pace.

"Ed is the other one. He has worked as hard as he could and he will have to pass a fitness test by Thursday to be in the running."

Gloucester have reached the play-offs for the first time since 2011, but European champions Saracens now stand in their way at Allianz Park.

Ackermann is under no illusions how big a task lies ahead, with Saracens two wins away from securing a European and domestic trophy double.

"It is a one-off game, with no bonus points, but from a preparation point of view we try and stay to the same routine and keep the same intensity in training and tick all the normal boxes," he added.

"You can't look at any other games that we've played during the season because it is going to be a one-off game.

"We respect Saracens for what they have achieved.

"Over the past seven years, they have produced a lot of international players and a quality squad, which means it is a massive challenge. We know we are up against the best team in Europe.

"We have got a chance. If we didn't finish in the top four, we wouldn't have had that chance.

"You have to stay true to yourself and do the same things. You can't suddenly want to change a lot because it is a play-off."

Both Ackermann and Gloucester skipper Willi Heinz have previous play-off experience in Super Rugby, although a Premiership semi-final will be a new experience.

Heinz said: "One of the biggest learnings I've had from finals weeks is that you have got to enjoy them.

"You have got limited time left with each other and you want to give yourself the chance of one more week in the season, hopefully.

"We know that Saracens are a champion team. There are not too many deficiencies in their game, and we need to be on top of our game.

"Sometimes, Saracens can be lumped into that boat of being super-physical and kicking the ball, but there is more to them.

"They can play with real pace and tempo, and they've got some intricate plays that can pick you apart as well.

"We have got to go there and believe in ourselves, which I know we will do, and put in a really good account of ourselves."