The Manchester City boss said it is ‘ridiculous’ that the two youngsters were not automatically given a medal with the rest of the squad when the presentation was held on the pitch after the Huddersfield game.
Foden and Diaz, along with fellow academy products Tosin Adarabioyo, Lukas Nmecha, Daniel Grimshaw, Aro Muric, were all announced, and walked up to the podium after Guardiola.
But league rules state that for a player to receive a medal on the day, they need to have made a minimum of five appearances – with the exception being the reserve goalkeeper.
None of the youngsters had played that many games, but both Foden and Diaz now stand on four appearances – and if they play in the final game at Southampton on Sunday they will be given a medal by rights.
Brahim Diaz made his forth appearance of the season against Brighton in midweek, so needs one more to automatically get a winner’s medal
Even if they do not, it will be at the club’s discretion whether they receive one.
The club is handed 40 medals, and must give them to all players who make at least five appearances.
The first 22 medals were handed out to Guardiola and the qualified players on the pitch, and the manager’s backroom staff will all get one.
City have not yet discussed how to distribute the remaining medals, but it is almost certain that the six young players who missed out will get one.
The fact they were not automatically given one – and had to walk up to the podium before walking away with nothing around their necks, has angered Guardiola.
Guardiola said he was unaware of the rule, but was not happy with it once he found out.
“I didn’t know it, but it looks ridiculous to me,” he said.
“If they want my medal, I will give them my medal. They are champions, they worked from the first day to the last one – training, in the locker room, more training.
“They didn’t play because of my decisions, but it’s the same. Tosin, too, from day one in training with us.
“They are champions — it doesn’t matter they don’t have medals.
“Maybe it’s so expensive to give three, four or five medals for the young guys. They are all the time training with us.”