"It's good and I'm happy to see these good players coming in," Ayew told the Hammers' official website. "I think we have a good squad, but now we have to do the job on the field and that's another thing altogether.
"We already had good players in the squad and now we've added some more good players, so that's really important for a club like West Ham to get to another level.
"I feel like we are going to be capable of doing good things but we need to stay humble, work hard and don't think we have done it before time."
West Ham's opening league match will be against Manchester United at Old Trafford on August 13.