Kallum Watkins and Carl Ablett are in a race against time to be fit for Saturday's Carnegie Challenge Cup final against Wigan.
Watkins twisted his knee and Ablett an ankle during the Rhinos' 32-22 surprise defeat by strugglers Harlequins at the Twickenham Stoop on Saturday.
Leeds coach Brian McDermott said: "Carl Ablett was caught in a tackle, which could have had a serious injury to his knee - as was Ali Lauitiiti. I'm just hoping it was an unfortunate coincidence."
Jamie Peacock, Jamie Jones-Buchanan and Ryan Bailey were all rested on a day to forget for former Quins coach McDermott and the Headingley boss said he would be monitoring the fitness of his key players.
He added: "Jamie Peacock didn't play as a precaution. He's done some miles on the bike, so we thought he'd be best sitting out this game."