Guardiola said Foden, who started three of their last 10 Premier League games, asked for time out to rest and recover from the injury.
City's 14-point lead over Liverpool in January has been reduced to just one point after Juergen Klopp's team won 10 consecutive league matches.
Foden stroked home in the 16th minute from Kevin de Bruyne's pass and it proved sufficient to seal a 10th successive league win for Pep Guardiola's relentless champions.
Foden sat out England's final training session ahead of the clash as a precaution due to a foot injury.
Manchester City scored twice in the second half through Mahrez and Foden to beat Borussia Dortmund on Wednesday and reach the Champions League semi-finals.
The 20-year-old midfielder scored his eighth goal of the season as City beat Premier League strugglers Brighton 1-0.
Calvert-Lewin has earned his first call-up to the senior England squad while Phil Foden and Mason Greenwood were dropped for disciplinary reasons.
Phil Foden fired Manchester City back to the top of the Premier League as the young midfielder sealed a vital 1-0 win over Tottenham, while Brighton improved their survival prospects with a goalless draw at Wolves on Saturday.
England returned from a 0-2 defeat against Spain in the 2017 FIFA U-17 World Cup final to win the game 5-2
Phil Foden, 17 years, shined in Manchester City pre-season tour and he is expected to have a role in Manchester City new season.