Bradford Bulls forward John Bateman and scrum-half Luke Gale are both in danger of missing the start of the 2013 Super League season.
Bateman, 19, could miss the first month of the campaign as he faces 12 weeks out for a shoulder reconstruction.
Gale, 24, needs ankle surgery and is likely to be out for two months.
Bulls coach Francis Cummins told the club website: "It's really disappointing for both players as well as the club."
Bradford start the season with a home match against Wakefield on 3 February.