Texan-born Spies, 33, raced in MotoGP full-time from 2010-12, joining the factory Yamaha squad alongside Jorge Lorenzo after an impressive rookie season at Tech 3.

He moved over to the Pramac Ducati squad in 2013, but was recovering from a major shoulder injury sustained the previous year when another crash at Indianapolis effectively forced him to call time on his professional career.

Since then, the former AMA and World Superbike champion has not raced, although recent reports have suggested Spies could be planning a racing comeback, possibly in the MotoAmerica series.

Speaking to Motorsport.com at the EICMA motorcycle show, Spies confirmed his shoulder had become strong enough for him to begin considering a return to racing.

But he admits that putting together a deal to race after such a lengthy absence will be a tall order.

“I’ve been riding a lot of dirt bikes this year,” former Dutch TT winner Spies said. “Now I am able to ride my dirt bike as hard as I can again, it’s only been like that through the last year.

“So we started to think about what options are out there. But it’s tough. I’ve been away for four and a half years now, so, for something to happen the way I want it to happen, it is probably difficult.

“Being away for four and a half years, if I was to come back, it would have to be the same deals as what I left, or I do not come back.

"That’s the problem. There is not much money in racing right now.

“We’ll see, my door is kind of open and we’ll see what happens, but I think it’s been a little bit too late now, so it will be tough.”

Spies says a decision on his future will come in the next two weeks, but if a return to circuit racing doesn’t come off, he could try his hand in off-road competition.

“Next year I am actually starting to plan to race off-road, dirt bikes, professionally,” he revealed.

“So, if I don’t come back on the road, I’ll be on the dirt in the US.”