The midfielder, on loan from Gillingham, enjoyed a superb debut in the 2-1 win at Bradford City last month.
But a hamstring strain has ruled Montrose (pictured) out for the last three games, when the U’s have stumbled, picking up one point from a possible nine.
“It was a great debut because we got three points and that’s the main thing,” said the 24-year-old.
“On the other hand, it’s been very frustrating for me having to watch.
“The main thing is to get back playing and performing to help win games.
“All of us need to step our game up and rise to the challenge for results, because that’s what it boils down to.”
United manager Chris Wilder is looking forward to welcoming Montrose back into the fold.
He said: “I’m sure in the last couple of games, which were tight, people like him can make the difference.
“We wanted to bring him in because we needed a bit of strength in the middle of the park, especially at home, in the second half of the season.”
Montrose will help fill the hole in midfield left by Peter Leven, who has begun an eight-week recovery from knee surgery this week.
It will also be a home debut for goalkeeper Luke McCormick, while Andy Whing is poised to be on the bench after playing 45 minutes in the Oxfordshire Senior Cup on Wednesday.
Top scorer Tom Craddock (groin) is not ready for a return, so Justin Richards will play up front with James Constable.
Wilder saw Rovers draw 1-1 at Cheltenham Town on Tuesday, which extended their good run under John Ward.
Since the ex-Colchester boss took over in December, the Pirates have lost just once in seven matches to climb out of the npower League Two drop zone.
With no new injury concerns, they are expected to be unchanged.
Oxford Utd: McCormick, Batt, Raynes, Wright, O’Brien, Potter, Chapman, Montrose, Rigg, Richards, Constable, Smalley, Parker, Heslop, Whing, Capaldi, Worley, Davis, Crocombe.
Bristol Rovers: Mildenhall, Smith, Parkes, McChrystal, Brown, Anyinsah, Norburn, Clucas, O’Toole, Woodards, Brunt, Gough, McDonald, Broghammer, Clarkson, Richards, Harrison, Hitchcock.