Rooney, 28, missed United’s 2-0 win at Stoke in the League Cup quarter-finals on Wednesday, but Moyes is desperate for the England forward to be fit to face the Hammers as he tries restore the champions to the Premier League title race.
United are already 10 points adrift of leaders Arsenal heading into this weekend’s fixtures and, with Robin van Persie out for a month with a thigh problem, Moyes needs Rooney, who has scored 10 goals so far this season for his club, to climb off the treatment table.
“Yes he has a chance to play,” Moyes said when questioned on Rooney’s fitness.
Meanwhile, Ashley Young is hoping his first United goal since May 2012 will give him a chance of starting against the Hammers.
The England winger had been exiled by Moyes after a lacklustre start to the season, but he lashed in a fine second-half strike at Stoke to help United on their way to the last four.
“I was delighted to get the goal, but getting through was more important,” he said.
“The boys were magnificent. We showed great spirit and character and hopefully we can take that into this weekend’s game against West Ham.”
Patrice Evra also got on the scoresheet against Stoke, but the French left-back insists he has to maintain his defensive performances rather than worry about getting on the scoresheet.
“I always say that I have played for many years at United and I know I can score more goals,” he said.
“But I am a defender and my first job is to defend. The name of the game now is to play with a clean sheet because, when we do that, we know we can win the game.
“It’s a strong performance (against Stoke). So now we are really focused on Saturday.”
United midfielder Michael Carrick will miss Saturday’s game as he recovers from an Achilles problem with Serbia defender Nemanja Vidic also a doubt for Moyes’s men.
Meanwhile, West Ham’s midweek 2-1 victory at Tottenham in the League Cup quarter-finals gave Sam Allardyce’s team a welcome lift after a disappointing run of results in the league.
The Hammers are just one point clear of the bottom three and, having lost four of their previous five games, their confidence had slumped before the win at White Hart Lane.
But Matt Jarvis, the scorer of the first goal against Tottenham, believes the London derby success can have a knock-on effect in the league while demonstrating the players are fully behind Allardyce.
“The Tottenham win could be a massive springboard for us and it’s just what we needed,” Jarvis said.
“It was a hard-fought victory and a massive confidence boost for ourselves.
“It doesn’t get any better for us, getting a win away from home against a big rival and playing as well as we did.
“I don’t think it has ever been in doubt (that the players are behind Allardyce). We work extremely hard and show great team spirit. We back the manager and it came out against Spurs.
“Can we get a result at Manchester United? I don’t see why not. Teams have gone to Old Trafford this season and got results.
“They’re still a fantastic side but we can go there full of confidence after this result.”