Injury to Worcester number eight Kai Horstmann means back rows Adam Balding and Richard Muagututia have a chance to force their way into the Warriors side against Northampton on Friday.
"It's up to one of those two to step up," Worcester coach Richard Hill told BBC Hereford and Worcester,
The pair both start in the Warriors A side against Exeter on Monday.
"We need to see what they can do and if they are worth a place," Hill added.
Samoa international Muagututia joined the Warriors two weeks ago, while Balding has played almost 200 games in the Premiership for Leeds, Leicester, Gloucester and Newcastle.
Hill will also be looking at his line out options after several turn-overs in 17-15 defeat to Harlequins on Saturday.
"Some of our systems were not good, some of our calling was not good," he continued.
"Chris Jones can do that and we were more than happy with him in training, and he is an England international.
"But our line-out did not function without Craig Gillies starting."
Hill has named a strong side for the game against Exeter, with club captain Chris Pennell, wings Tom Arscott and Josh Drauniniu, centre Alex Crockett and prop Ceri Jones all among the starting line-up.
Warriors: Pennell; Arscott, Crockett, Tu'ipulotu, Drauniniu; Carlisle, Dudley; Ceri Jones, Hayes, Tomaszczyk, Dacres, Gulliver, Balding, Betty, Muagututia.