Torquay United captain Luke Young will be out for at least six months after suffering cruciate knee ligament damage, the club has confirmed.
The 22-year-old former Plymouth Argyle midfielder, who played 39 league games for Torquay last season, was injured during pre-season training last month.
The Gulls open their league campaign against Macclesfield on Saturday.
Meanwhile, Torquay have signed centre-back Jamie Richards and striker Malachi Lavelle-Moore on non-contract deals.
Lavelle-Moore, 20, left Macclesfield in the summer, and could face them on Saturday when the two teams meet at Plainmoor in the National League.
Both have been part of Torquay's squad during pre-season, with the club bringing in 13 new players this summer.