"He came into the shed and had felt a bit of a twinge at the top of the hamstring. You wouldn't read about it," said coach Stephen Kearney.
"It's pretty early to tell at this stage. He had pretty good strength in it when he came in, it just didn't feel 100 per cent right and obviously it's been a long layoff for him and the last thing we want to do was make it worse.
"So it's too early to tell. We'll have to see how it pulls up in 24 hours."
The former Manly and Parramatta five-five-eighth has not played in almost a year since suffering a season ending shoulder injury last May before being granted a release from the Eels.
The Kiwis international signed a one-year deal with the Warriors last September and moved to New Zealand to get his life and career in order after battling numerous off-field dramas that saw him spend time in a rehabilitation clinic.
Foran's contract was finally registered by the NRL last month and after serving a two-game suspension over the opening rounds he was declared fit to make his comeback before fate intervened.
The Warriors have now lost three games in a row to leave them languishing in 14th spot on the NRL ladder, with their round one win over Newcastle now a distant memory.
It's imperative they get their campaign back on track with back-to-back home games against the Titans and Eels over the next fortnight before a difficult away trip to face the Raiders in Canberra.