New Zealand defender Reid has been back in training after being sidelined for almost a month due to a hamstring injury and is set to line up against Nigel Pearson's strugglers.
Valencia has been out of action after a broken cup lacerated his foot in a freak accident, and the trip to face the bottom side in the Premier League appears to have come too soon for the Ecuador striker.
West Ham manager Allardyce said: "We've got Winston Reid back in full training, but I don't think Enner Valencia is going to make it, although he is back in some sort of training.
"Winston will be available as he's had the last seven days back in full training.
"The timing of the international break was okay because it allowed us to get Winston Reid fit."
Allardyce's men are ninth in the table after beating Sunderland before the international break and the former Blackburn Rovers boss is eager to finish the season on a high note.
He said: "It's very tight between eighth and 10th now for us. We have a reasonable run-in, although no game is ever easy at this level.
"For us it's about achieving as many points as possible in the run-in. Hopefully we can kick off on a good run having beaten Sunderland."
