Ipswich Witches team manager Pete Simmons has admitted he is considering re-declaring his line-up for 2009.
Both Kozza Smith and Leigh Lanham picked up serious injuries in the opening meeting of the new season.
"We have been caught out in the past trying to cover for injured riders with rider replacement," said Simmons.
"We want to judge the teams performance on Thursday against Belle Vue in the Knock-Out Cup first round clash at Foxhall Stadium."
Smith - who is recovering from chest and shoulder injuries - is aiming to be back in the saddle in around six weeks, while Lanham plans to return in three to four weeks after having surgery on a hand injury.
Jarek Hampel and Dawid Stachyra are both expected to return to the Witches team on Thursday after missing last week's defeat at Lakeside Hammers with minor injuries.