The forward has missed the past three matches after cutting his toe when he stepped on the pieces of a smashed mug at his home.
However, Valencia - who joined from Pachuca in July - is line to face Mark Hughes' men at Upton Park after coming through training unscathed.
"We can add Enner Valencia to the squad from last week because he's had a good week's training. He's back in contention," Allardyce said.
"He gives us other options to play different systems. To have selection choices up front is important for any team."
After a superb start to the season, West ham have struggled since the turn of the year and have won just once in their past nine league matches to leave them ninth.
Allardyce believes that the problem has not been in creating chances, but more in West Ham's failure to convert opportunities.
"The wins have eluded us recently and hence we're disappointed with where we are in the league, but not with the performances," Allardyce added.
"The most important thing is Saturday's game and not beyond that - to beat Stoke at Upton Park.
"Our all-important factors are that our creative capability has been endless all season, but what we haven't done is convert as many chances as we were before.
"The other end is concentration [and] not letting the opposition score when you're in control of the game."
