For the Premier League’s biggest clubs, this competition is usually an opportunity to blood youngsters and give fringe players valuable minutes.
However, only 35-year-old Danny Welbeck, who scored twice, emerged from the starters with a compelling case for more regular involvement.
Even Valentin Barco, despite scoring Chelsea’s fifth goal, was partly at fault for Leeds’ second and was among several players who repeatedly surrendered possession during a difficult first half.
Young attackers Estevao Willian and Jamie Gittens suffered the disappointment of being substituted at half-time, while £40m signing Geovany Quenda, who joined from Sporting, did not add to his solitary substitute appearance for the club as he watched from the bench.
Midfielder Reggie Watson, making his debut at the age of 16, was also withdrawn at the break after being booked.
Alonso later said he would not take a “cynical” view as some on the outside might about the difference in level between his proven stars and Chelsea’s back-up options.
He added: “I know that probably I have to take the right decisions for them to show their best level, so it’s something that I will analyse and learn from today.”
Nevertheless, reaching the fourth round is important for Chelsea.
It is not only about preserving their hopes of silverware in a season without European football, but Chelsea are also a club that need as many competitive fixtures as possible.
They have a 27-man squad, supported by a strong academy pipeline, and these matches are vital for keeping a large group of players engaged throughout the campaign.
There is an irony, then, that Palmer, Rogers and Chelsea’s other established stars may have secured future opportunities for the very fringe players whose performances had put the club’s EFL Cup campaign at risk.