Widnes Vikings expect to be without front-row forward Alex Gerrard for eight weeks because of a knee injury.
The 21-year-old tore his posterior cruciate ligament during in the fourth round of the Challenge Cup.
with the Super League club in February.
Meanwhile, long-term absentees (collarbone) and (shoulder) are close to returning.
Utility back Craven has not featured since the opening weekend of the campaign, while centre Marsh was hurt at the start of March.