Leinster were unable to shed their losing habit in Champions Cup finals after they were edged 31-22 by Toulouse with only extra time separating the rivals at Tottenham Hotspur Stadium.
Leinster fended off a second-half comeback to beat Northampton 20-17 in the Champions Cup semi-final at Croke Park.
Leinster dropped from the top of the United Rugby Championship standings after losing 42-12 to the Stormers in Cape Town.
Prop Brok Harris will become the first player to reach 150 appearances for the Stormers in the URC clash with Leinster at DHL Stadium on Saturday.
Ruben van Heerden says the focus this week is attitude and intensity as the hardworking Stormers lock embraces the challenge of a massive clash with Leinster at DHL Stadium on Saturday.
The Lions took full advantage of going up against a weakened Leinster outfit at Ellis Park on Sunday, as they romped to a 44-12 URC victory.