The Hammers have made an impressive start to the new season following their Europa Conference League triumph in June, winning three and drawing one of their opening four Premier League matches.
West Ham entered the international break after beating Chelsea, Brighton & Hove Albion and Luton Town, securing a 2-1 win away against the latter in their last match two weeks ago.
Moyes has since revealed that he and his players have enjoyed their time together during the international break, but has admitted that a few players have returned from representing their country with "knocks".
James Ward-Prowse, who did not represent England earlier this month, allegedly picked up an injury last week but he has since taken part in training and should be fit to feature on Saturday.
Meanwhile, Vladimir Coufal has emerged as a doubt after missing Czechia's Euro 2024 qualifier against Hungary last Sunday with a "small" injury.
Furthermore, Moyes has commented on a delayed flight for Mexican summer signing Edson Alvarez, but the Hammers boss believes his squad are in good shape for the challenging contest against Man City at the London Stadium.
Speaking at a press conference on Friday ahead of their encounter with the Citizens, Moyes said: "We really enjoyed the international break because of the season we've had so far. We've been able to enjoy this one and the players have worked hard during this period as well. We're hoping that all the boys that have returned are fit and well.
"Some of them have picked up little bits of knocks and I think the travelling doesn't help. Edson Alvarez had a delayed flight and didn't get back until yesterday [Thursday] at about three o'clock, but it's part and parcel of the international breaks. We're hoping that we'll have everybody fit and available."
Alvarez joined West Ham from Ajax in the summer for around £34m and has since made a bright start to life at the London Stadium, starting in the last two victories against Brighton and Luton as a defensive midfielder.
"[Alvarez has] had a great start in the Premier League," said Moyes. "As an overseas player it's never easy to hit the ground running in the Premier League. I think he's got off to a great start for us and he's made a great impression with everybody.
"He's shown a brilliant mentality and character in training. He's working really hard and settled in well. We're enjoying having him here."
Moyes has also been impressed with the impact of fellow new recruit Ward-Prowse, who has contributed with one goal and three assist in his first three Premier League games for West Ham following his £30m move from Southampton.
"We're pleased to have him here," the Scotsman added. "It's not like he needed any sort of pre-season with us because he's well down the road with that, and he was probably a little bit unlucky not to make the England squad.
"It's great to have him and it gave him the chance to have a couple of days rest as well, which hopefully he'll benefit from."
West Ham are hoping to end their 15-game winless streak against Man City and consolidate their place in the top four of the Premier League when they welcome the reigning champions, who are yet to drop a single point this term, to East London this weekend.