The Aviva Premiership semi-final line-up will be confirmed on Saturday with the final round of matches in the regular season.
Exeter Chiefs, Saracens, Wasps and Newcastle Falcons have all qualified for the post-season with this weekend's action set to decide the exact line-up for the final four and the qualifiers for next season's Champions Cup.
Defending champions Exeter have already secured top spot and with it home advantage in the semi-finals that will be staged on May 19.
Rob Baxter's side have won their last six league games and will look to maintain their momentum against a struggling Harlequins outfit who will also bid farewell to director of rugby John Kingston at the Twickenham Stoop.
Three-time winners Saracens ensured they will finish second and also host a semi-final with a thumping victory over London Irish last weekend.
They face Gloucester at Allianz Park with the Cherry and Whites battling to hold onto sixth place in the table and with it qualification for the Champions Cup.
Gloucester could also qualify for the Champions Cup next season with victory over Cardiff Blues in the European Challenge Cup final on May 11.
Wasps are currently third in the table, three points ahead of Newcastle, and as things stand they will tackle Saracens in the semi-finals with the Falcons poised to take on the Chiefs.
However, all could change on Saturday with Newcastle and Wasps set to go head to head at a sold out Kingston Park in a game that will confirm their final placing and the play-off picture.
Fifth-placed Leicester's last-gasp defeat to Newcastle last weekend ended the Tigers' hopes of a 14th consecutive appearance in the play-offs and they now face a battle to hold onto their place in the top six.
They must travel set seventh-placed Sale Sharks who will be seeking a bonus-point win that would guarantee them Champions Cup rugby next season - if they also deny Tigers a match point.
Any kind of victory would also see them finish in the top six as long as Gloucester leave Allianz Park with no more than two match points.
Irish's relegation to the Championship was confirmed last weekend with Worcester Warriors securing the result they needed to end their rivals' mathematical hope of avoiding the drop.
Irish wrap up their season against Bath at The Rec where the hosts need a bonus point win to keep their Champions Cup hopes alive but they will also need qualification rivals Gloucester and Sale to slip up.
The weekend's fixtures - that all kick-off at 4pm - are rounded out by the Warriors' clash with Northampton at Franklin's Gardens with Saints desperate to add some gloss to a disappointing and troubled season.