City were dealt a blow in the week with the news that De Bruyne is out for three months with a knee injury suffered in training.
Academy product Foden only played 44 minutes in the Premier League for City last season, but could get more opportunities with De Bruyne missing.
Ahead of City’s clash with Huddersfield on Renault Super Sunday, Guardiola told Sky Sports: “Of course Phil is special, but he is a young player so we have to be patient.
“His behaviour is important. On and off the pitch he is excellent, that is the first step to becoming a good player. He will play a lot of minutes and have games to play and go step by step. We cannot forget he is 18 so he is young.
“Be patient, work hard, listen and see what happens, we will help him to be a better player.”
While Foden might get more minutes over the next three months, Guardiola admits City will miss De Bruyne.
“We cannot deny how important Kevin is,” he said. “We are going to miss him but we have to help him. It’s time for him to rest a bit after a tough season, have a bit more holiday and then start to prepare to come back and think about the players we have fit to win games.”
Looking ahead to City’s first home game of the season, Guardiola added: “We are excited.
“We always prefer to play at home than away but of course after last season we start again at home and hopefully we can make a good game.”
Watch Manchester City v Huddersfield live on Sky Sports from 12.30pm on Sunday