De Bruyne was substituted during the closing stages of Saturday's 3-1 Premier League win at Everton, when he appeared to be discomforted by a groin issue.
The Belgium international did not take part in the section of City's pre-match training session that was open to the media on Monday, and so looks set to be a doubt for the Champions League fixture with the Croatian side.
Zagreb sit top of Group C after one game, level on points with City but with a superior goal difference after beating Italian side Atalanta 4-0.
They now have 15 goals in their last four games in all competitions, with both sides heading into the fixture in second place in their respective leagues.
Having netted four times in their Champions League opener, the Croatian outfit will be looking to continue their goal-scoring prowess against a weakened City defence, with Pep Guardiola's side now potentially also without their star midfielder.
De Bruyne has recorded eight Premier League assists this season, twice as many as any other player, with only Arsenal's Cesc Fabregas in 2009/10 providing as many in his side's first seven games in a single campaign.
Pep Guardiola's side welcome Dinamo to the Etihad Stadium having won their Group C opener 3-0 away to Shakhtar Donetsk, where the 28-year-old claimed the assist for Gabriel Jesus' first and City's third of the game.
The City boss has had to reshuffle his squad after defenders John Stones and Aymeric Laporte were ruled out with long-term injuries, and says his team must come together to battle through the situation.
"It is a tough moment for the team, but this only makes us stronger for the next months," Guardiola told reporters ahead of the game.
"We have to be all together. It is not an excuse."
“We can’t give up in our challenge this year. We must keep going and fight in all the games. I think we have enough players to deal with this problem.”