Pep Guardiola said the gruelling demands placed on his Manchester City players by an intense schedule means he will be forced to make changes to his line-up in the coming weeks in order to protect their welfare.

City face four games in 11 days, beginning with Tuesday's Champions League opener against Red Star Belgrade at the Etihad, before welcoming Nottingham Forest in the Premier League on Saturday.

They play Newcastle in the Carabao Cup third round on September 27 and travel to Molineux to face Wolves three days later, all off the back of an international window that saw several of Guardiola's team endure long trips to and from South America.

City came from behind to beat West Ham 3-1 at the London Stadium on Saturday, with Julian Alvarez and Ederson playing key roles despite having returned only days earlier from international duty with their respective national teams Argentina and Brazil.

Guardiola singled out West Ham's Edson Alvarez, who played for Mexico in their 3-3 draw with Uzbekistan in Georgia in the early hours of Thursday before starting for David Moyes' team on Saturday.

He lasted 66 minutes before being withdrawn, but Moyes confirmed there was no injury and he was only looking to preserve Alvarez's fitness.

Nevertheless, Guardiola shared his concerns over the impact the schedule is having on players.

"It is a problem when you have a lot of injuries," he said. "The problem is not today, it's in three, four, five games. We have the Carabao Cup away at Newcastle, I'm sorry but we will have to use (from) the second team some players.

"Kevin (De Bruyne) is still out, John (Stones) is still out, Mateo (Kovacic). Jack (Grealish). When you have all the squad you go to Newcastle with a good team and whatever. Right now, it is just to rest, to recover well, training (to get) fit and to arrive on the day of the game in the best condition possible.

"We cannot waste energy because otherwise, these guys who have been playing for the national team, travelling from Bolivia (Julian Alvarez), from Brazil (Ederson) - it's so exhausting for them.

"Look at Alvarez from West Ham, 15 or 20 minutes after half-time, he's out. Why? He's come from South America, he's jetlagged - 12, 15 hours, he's come here, played against City. We treat the players in not a good way. We are so responsible for how we treat the players."

Guardiola added that he was in awe of the physical condition of Kyle Walker, who returned to City's line-up after scoring his first goal for England in the draw with Ukraine and put in a clinical performance against West Ham.

"I would say I'm not surprised (by his physicality), I've worked with him for seven years," said Guardiola. "But I have to admit that when he is stable and happy, he has (this) ability.

"His mum and dad gave him some genetics that our mum and dad didn't give to us."

READ MORE: Son Heung-min hails Richarlison's stunning turnaround

SHACARRI RICHARDSON

Sha'Carri Richardson anchors U.S. 4x100 relay to Olympic gold

St Lucia's Julien Alfred makes history as she sprints to Olympic gold medal

Editors Pick