Bath host Wasps on Saturday knowing that victory would keep them in third place with just seven league games remaining in the Aviva Premiership.
Although they are 10 points behind second-placed Saracens and 11 adrift of leaders Northampton, the West Country club are unquestionably genuine title contenders.
Meanwhile, Wasps arrive at the Recreation Ground on the back of a home defeat against 14-man London Irish.
Bath head coach Mike Ford has made five changes from the team that gained an impressive win at Exeter last time out.
Tom Heathcote starts at fly-half instead of Ford's son George, who is on England duty at Twickenham, with other switches including starts for props Nathan Catt and Juan Pablo Orlandi, plus lock Dominic Day.
Hosts Bath have suffered just one defeat in the Premiership since the end of December while Wasps have slipped to three straight defeats in all competitions.
Wasps field a team showing three changes in the pack as hooker Tom Lindsay, lock James Cannon and back-row forward Nathan Hughes all gain starts. One switch in the back division sees an opportunity for scrum-half Charlie Davies instead of Joe Simpson.
Former England centre Mike Tindall will make his 200th Premiership appearance, captaining a Gloucester team against Harlequins at the Kingsholm Stadium.
Gloucester director Nigel Davies makes three changes up front after last weekend's narrow loss against Leicester with a switch in each row of the scrum.
He also hands call-ups to prop Rupert Harden, lock James Hudson and number eight Gareth Evans.
"It's an amazing achievement, it really is," Davies said of Tindall's landmark.
"The fact of the matter is that he's not just making his 200th appearance, he is actually playing very well at the moment. He was outstanding last weekend up at Leicester.
"Someone like Mike adds a lot of value to the team, a lot of the stuff that you don't see in terms of the way he energises and drives the group."
Gloucester head into the clash having suffered three successive defeats in the Premiership since beating Irish at the end of December.
But Quins have lost their last two away games - although they have not lost three in a row on their travels since April 2011.
Centre Tim Molenaar will face his former club, lining up in the Harlequins' midfield as replacement for Jordan Turner-Hall, who suffered a knock in training this week.
Elsewhere, prop Kyle Sinckler makes his first start of the season and lock George Robson returns to partner Nick Kennedy in the second row.
Premiership try tally
Sale wing Mark Cueto will look to increase his Premiership try tally of 84 - an ongoing league record - against Worcester.
He makes his 200th Premiership appearance in a side that also includes the likes of Danny Cipriani, Dwayne Peel, Dan Braid and James Gaskell.
Sharks were defeated 10-15 at home to Saracens on Friday but have picked up at least one league point from their last eight encounters.
Worcester head into the game having lost their last 19 Premiership fixtures, only Rotherham have a worse sequence, with 30 successive losses between 2001-2004.
Wales international Jonathan Thomas misses the Sixways clash due to suspension for the hosts after being sent off in last weekend's game against Northampton, so Mike Williams, Sam Betty and Leonardo Senatore form a rejigged back row.
One other change sees a return to action for lock James Percival.
"This is an opportunity to put in another shift, and if we reach the level we have in the last two weeks, we might get something from it," Worcester rugby director Dean Ryan said.
"We're getting some unity around the group week after week, and if we can do it again we will cause problems for Sale."