McGeechan’s men have stormed into the play-off picture following eight successive Premiership victories since Gloucester beat them 18-17 at Kingsholm more than three months ago.

Wasps have rattled up 265 points in the process and they also hold a game in hand - against Newcastle next Wednesday night - on Gloucester and second-placed Bath.

Gloucester though, have the incentive of knowing a win at Adams Park would confirm their play-of place one match inside the distance.

McGeechan said: “Gloucester have been good all season, that’s why they are top.

“This game is without doubt our biggest challenge of the season so far.

“Gloucester produce quality rugby on a consistent basis, and we have to perform on Sunday to challenge them.

“We have had to fight our way into the top four, and I’ve no doubt that the race for the play-offs will go right down to the wire next Saturday.”

Gloucester’s play-off confirmation is tantalisingly close, but so close is the top-four race that defeats in their final two fixtures against Wasps and Bath could see them miss out completely.

“We are very aware of what Sunday represents in terms of the challenge we face and what we have to do to match it,” said Gloucester head coach Dean Ryan.

“It is about a physicality level we have experienced at the top end of Europe, and we will be ready for that.

“Wasps are an outstanding side, well-schooled in the arts of knockout rugby, and that is what makes the challenge very exciting.

“But we need to concentrate and focus on our game and getting the maximum out of the threat we can create. If we can do that, then I am positive we can stretch any team we come up against.

“We have given ourselves an opportunity towards the play-offs, but nothing has been accomplished yet, which is why this game means so much to us.”