They had a good go at it, losing first Charlie Faumuina and then Nic Mayhew to the sinbin at the end of each half and giving away an astonishing 15 penalties to the Force's three.
"It's something we need to find a solution to because after the break, we went away from what was working for us and made a couple of errors," Umaga said. "All of a sudden, we're defending for 35 minutes, which is pretty tough. Our discipline didn't help either with two guys in the bin and giving away silly penalties."
Umaga said of the Crusaders, who comprehensively beat the Waratahs 29-10 and will welcome back giant wing Nemani Nadolo for Saturday: "It's very tough. They're the form team and we're probably the competition battlers. We've got nothing to lose, we're playing at home after being away for three weeks. It's not hard to get ourselves up for it."
Umaga will await injury reports on prop Ofa Tu'ungafasi's concussion and the ankle injury which ruled out front rower Sam Prattley. Matt McGahan, like Prattley, was ruled out of the match late in the week, although in the case of the inside back it was after the captain's run. McGahan suffered a leg injury in kicking practice. There is a suspicion, too, Faumuina has a calf strain, and flanker Tanerau Latimer a knee issue.