Tranmere are without Andy Robinson and Adam McGurk after boss Ronnie Moore revealed he expects the pair to miss both Easter weekend fixtures.
Playmaker Robinson remains sidelined with a groin complaint, while winger McGurk continues his recovery from a collapsed lung.
Moore believes Easter Monday's long journey to Portsmouth is also out of the question for the duo, targeting the subsequent trip to take on League One leaders Doncaster.
He told Tranmere Player: "We were hoping that they would be fit but the games probably come too early for them but I would imagine they would both be okay for Doncaster."
Rovers head into the vital clash a point and a place above United having played three games more than their rivals and Moore prescribed further rest for his team this week after the tactic paid dividends ahead of Sunday's 3-1 triumph over Stevenage.
"We gave everyone three days off last week which we think helped and improved them, so we've given them rest again this week."
Sheffield United striker Jamie Murphy is in a race against the clock to prove his fitness.
Murphy would have missed last Saturday's postponed fixture with Brentford due to a hamstring injury sustained in the recent defeat at Stevenage and remains doubtful, but could play some part if he passes a late test.
Manager Danny Wilson, who has no new injury or suspension problems, could recall on-loan pair Jonathan Forte and Dominic Poleon in Murphy's absence, while teenager Callum McFadzean, who replaced the former Motherwell forward at Stevenage, is hoping to make his first league start for the Blades.
Defender Danny Higginbotham and striker Chris Porter, back from his loan spell at Shrewsbury, are also in contention, but teenager Diego De Girolamo and defender Lecsinel Jean-Francois both remain sidelined following knee surgery.
The Blades, chasing a second win in five league matches, are bidding to climb back into an automatic promotion spot.