Eastbourne are searching for a new heat leader after Adam Shields called time on his racing comeback.

The experienced Australian has retired due to fitness concerns in the opening weeks of the season.

Eagles now have four weeks to sign a new rider but will operate rider-replacement when champions Swindon visit on Saturday.

Shields cut short his 2012 season but denied he had retired.

However he has suffered back problems and concussion in recent weeks and also struggled for form after his loan move from Lakeside.

Eagles have about seven points to play with as they look for a new recruit.

Shields has admitted he was not enjoying his speedway in recent seasons due to off-track issues, including a divorce.

Team manager Trevor Geer: “He felt he was letting the team down and he did not want to do that.

“He thinks if he was riding like he could do we could win things.

“I think he has a lot going on these last few years and it is a job to keep your mind fully on speedway.”

Eagles are unlikely to find it easy to find a suitable replacement who can fit their fixtures into his diary.

They could be awaiting developments at Lakeside, who have signed experienced Polish racer Sebastian Ulamek but not yet announced who will be making way for him.

Lewis Bridger, who joined Lakeside on loan from Eastbourne in an exchange deal with Shields, has revealed via Twitter that he will be staying at the Essex track.

Meanwhile Eagles duo Timo Lahti and Cameron Woodward are both through to the second stage of qualifying for next season’s Grand Prix series.

Woodward finished eighth and Lahti tenth in a well-attended qualifier at Abensberg in Germany yesterday, both on eight points from five rides.

The top ten went through with former Eagles No.1 Scott Nicholls the first man to miss out as he came 11th on seven points.