Mitchell Moses is in doubt for the State of Origin opener as the New South Wales playmaker struggled with a hamstring issue, paving the way for a potential debut for Ethan Strange.

Five-eighth Moses trained with the Blues in Gosford today but will be sent for scans by NSW staff after complaining of tightness.

Laurie Daley's men relocated to Sydney today after completing an opposed session against Newcastle's NSW Cup team on the Central Coast.

The anticipated absence of Moses has led to NSW rushing Canterbury five-eighth Matt Burton into camp ahead of Wednesday night's game at Homebush in Sydney.

"The NSW Blues, subject to ARLC (Australian Rugby League Commission) approval, will call Matt Burton into the 20-player squad as stand-by for five-eighth Mitchell Moses, who pulled up with hamstring tightness at the end of training at Polytec Stadium in Gosford," the Blues said in a statement this afternoon.