Swindon Robins have released Russian rider Sergey Darkin.
Darkin was signed in August as a reserve rider to cover for the injured Chris Schramm and Josh Grajczonek.
But following the arrival of 17-year-old Mikkel Jensen last week, Darkin has been told he is now surplus to requirements at the club.
"Sergey did his job for us and in many ways he is the unlucky one. We wish him all the best," said Robins team manager Jan Staechmann
"Everyone knows it's been a tough season and we are already casting an eye towards 2012 by bringing in someone of Mikkel's talent."
Jensen will make his debut on Thursday against Peterborough.