Pep Guardiola's vision of Manchester City's future may have left Sergio Aguero and Claudio Bravo wondering how they will return to the starting XI.
Error-prone keeper Bravo was surprisingly dropped by Guardiola in favour of Willy Caballero for Wednesday night's trip to West Ham.
And striker Aguero also started on the bench as teenage Brazilian Gabriel Jesus inspired City to a thumping 4-0 win.
"Today Caballero was the first choice," said Guardiola. "I will sleep well and decide in the future.
"Was it a difficult decision? Yes, it was difficult.
"But three or four guys stayed in Manchester, that was difficult. I have 23 guys who deserve to play.
"Sergio remains an important player for us. I make decisions with my staff, depending on performances in the past.
"I'm a guy who likes to involve as many players as possible. In this crazy calendar it's impossible to play with the same guys. I try to be fair with my decisions."
The City boss was certainly vindicated as £27million new-boy Jesus gave West Ham the runaround on his full Premier League debut.
The 19-year-old, forming part a youthful three-pronged attack with Leroy Sane and Raheem Sterling, set up Kevin De Bruyne's opener after a mistake by Aaron Cresswell.
David Silva tapped in the second from Sane's cross and Jesus grabbed the goal his display deserved before half-time after being teed up by Sterling.
"He's 19, but he's already a striker for Brazil," added Guardiola.
"He attacks the goal, he wants to score. It's like a water melon. You have to open it and see. The prospect was good, a young player with good talent.
"These guys are the future of the club. In Europe no one has strikers as young as Manchester City."
Yaya Toure wrapped up the victory with a second-half penalty after Jose Fonte, enduring a miserable West Ham debut, tripped Sterling in the area.
Hammers manager Slaven Bilic was left with a familiar feeling, having seen his side beaten 5-0 by the same opposition in the FA Cup just over three weeks earlier.
"It's not the first heavy defeat, we have bounced back before and we have to do it again," he said.
"We have an opportunity to do that against Southampton in three days time."