Gray said: "We're hopeful. We'll wait and see how he comes through the next few days before making any decisions."
Gray is also hoping that none of his returning international stars have picked up knocks.
Alan Smith played only 30 minutes for England last night against Sweden, while Ian Harte scored a beauty in the Republic of Ireland's 2-1 win over the Czech Republic at Lansdowne Road.
Stephen McPhail missed that game due to a calf problem. Gray added: "Stephen has been struggling with a calf problem for a few weeks now and it was agreed that he wouldn't play.
"I spoke to Irish boss Brian Kerr and I'm grateful for his help and support. In our situation we need all the players available."
Mark Viduka featured from the start in Australia's win over South Africa on Tuesday night, creating the winning goal and coming off after just over an hour.
Stephen Caldwell was a non-playing sub for Scotland, while Paul Robinson was again on the bench for England last night.