Plymouth Devils have signed Czech rider Sam Simota as a temporary replacement for Alex Davies, amid a delay in securing a visa for the Australian.
Davies, who had been set to be the Devils' heat leader, has not yet received clearance from the UK Border Agency to work.
Simota, 28, previously raced for Peterborough and won the Czech Under-21 Championship in 2004.
Plymouth begin the season with a League Cup visit to Peterborough on 25 March.
Devils co-promoter Ashley Taylor said: "We are still working on completing the necessary paperwork for Davies to become part of our team, but it is difficult to put a timescale on things.
"We have spoken to Alex in Australia and we are totally committed to bringing him over here this season."
"For Sam, riding for us will give him the opportunity to put himself in the shop window with a view to subsequently earning a place with another track."
The Devils squad for the 2014 season is made up of Kalle Katajisto, Ben Reade, Ben Barker, Rasmus Jensen, Kyle Newman and Roland Benko, with Davies to be added once his visa issues are resolved.