Former Manchester City defender Danny Mills says it is "virtually impossible" for Pep Guardiola's side to win the quadruple.
City kept their hopes of winning four trophies alive when they beat Newport 4-1 to reach the FA Cup quarter-finals.
They now play Schalke in the Champions League last 16, and Chelsea in the Carabao Cup Final live on Sky Sports, before resuming their defence of the Premier League title.
Speaking on Sky Sports News, Mills said: "It's very, very difficult to win three, all four is virtually impossible. A mistake, a bad refereeing decision, anything can happen that means you can lose a game.
"But off the back of that he's got such a strong squad and he keeps rotating the side.
"They won't be training much at the moment, they are all very fit, they all know how to play the way the system works. Everybody knows their jobs so it's just game after game after game.
"Sometimes that can work to your advantage and you get on this roll, you get this belief, this confidence that you can win every single game.
"They've got world-class players that even if they are not quite being brilliant at the moment they can still win the game.
"So if anybody can do it, City have the potential to win all four trophies although that said it can take just one mistake, one slip, a wonder goal, a bad decision that can cost you and you only win three and not four.
"The Champions League is the holy grail, for the owners that is the pinnacle. To say you're the best team in Europe, better than Real Madrid, Barcelona, Bayern Munich, that has to be what they are after.
"The league is still incredibly important, they will want to win back-to-back titles.
"I don't think they have to prioritise one or the other. Their squad is so good they can go full tilt in the league and see what Liverpool do and they can go flat out in the Champions League and see what happens in that."