Eastbourne Eagles number one Joonas Kylmakorpi will be on the sidelines for at least three weeks.
The Finnish rider cracked his collarbone and damaged his shoulder socket in the 59-31 defeat at King's Lynn on Wednesday.
The reigning Long-Track world champion, 32, was taken to hospital for an MRI scan after crashing in the first heat.
Eagles team manager Trevor Geer said: "There was some bunching in the first corner and Joonas came off worst."
Kylmakorpi could miss up to eight Elite League meetings in April.