Bristol Rovers duo Adam Virgo and Wayne Brown are both facing lengthy spells on the sidelines because of injury.
Defender Virgo, 28, will undergo knee surgery on Thursday and could be out for two-to-six months depending on the severity of the cartilage damage.
Midfielder Brown, 23, has a stress fracture in his ankle and will be absent for three months.
"It's two big first-team members that we are losing," manager Paul Buckle told BBC Radio Bristol.
Virgo, who suffered the knee injury in training, is in his first season with the club and has made 11 appearances while Brown has played 12 games this term.
"It's shocking news for Adam - he's a great lad and is desperate to get his Rovers career up and running," said Buckle. "This is a major set-back for him and the club.
"We think we are on the way to getting on the road to recovery with they players and we get more bad news."
Buckle is now considering adding more loan players to his squad after Tuesday's game against Port Vale.
"I've spoken to the chairman and he's aware we are low on numbers now. We are going to have to try and strengthen," he said.
"It probably won't be this week as it's a little too close to Saturday. But we'll get Saturday's game [at Burton] out the way, obviously we've got another game almost straight away, and then we'll look at it."
Meanwhile, youngsters Kayne McLaggon and Michael Boateng will be joining Tunbridge on loan while Charlie Reece will join Gloucester City.