Pep Guardiola took off Erling Haaland against Slovan Bratislava to "take care" of Manchester City's superstar striker.
Haaland scored in the 58th minute to make it 3-0 to City in Slovakia on Tuesday.
He was taken off two minutes later, to be replaced by James McAtee, who went on to score his first City goal and round off a 4-0 Champions League rout.
With focus now switching back to the Premier League, and Saturday's clash with Fulham, Guardiola explained the substitution was made to protect the striker, who has already netted 10 goals in England's top flight this season.
Asked if Haaland had been frustrated to be taken off, Guardiola told City's media channels: "Erling is never disappointed with his manager.
"As a manager I am more secure and more happy when Erling is on the pitch.
"I will keep him on the pitch all the time but at 0-3 the game was almost over and with this amount of games we have to take care of him.
"He had a big knock in the last game against Newcastle [United] so that's why, after the fantastic goal with the pass from Rico [Lewis], it was better [to take him off]."
There was a moment of drama during Fulham's 1-0 win over Nottingham Forest last week, after Raul Jimenez took a penalty off the club's designated taker Andreas Pereira.
Jimenez went on to score the penalty, but Marco Silva was not happy.
He said: "It's clearly the fault of Raul. It is not going to happen again.
"Has Raul apologised? Yes. He had to because he knows the rules and how important discipline is in our squad."
City are unbeaten in their last 29 Premier League games (W23 D6), and if they avoid defeat in this match it will equal their longest run without defeat in their league history (30 games between April 2017 and January 2018).
PLAYERS TO WATCH
Manchester City - Erling Haaland
Haaland has scored 60 goals in just 52 games in all competitions at the Etihad Stadium for Man City. He is already the fourth-highest goalscorer at the ground since it opened in 2003.
Fulham - Andreas Pereira
Only Everton's Dwight McNeil (21) has created more chances than Pereira in the Premier League this season (20).
Five of these chances have been for Rodrigo Muniz, who has had more shots on target without scoring so far than any other player in the Premier League this term (five).
MATCH PREDICTION: MAN CITY WIN
City have drawn their last two Premier League games despite opening the scoring in both (2-2 v Arsenal, 1-1 v Newcastle). The last time they failed to win three consecutive league games despite scoring first in each was in December/January in 2003-04 (D2 L1).
Since losing their opening Premier League game of the season 1-0 at Manchester United, Fulham are now unbeaten in their last five (W3 D2). They last had a longer run without defeat in the competition between August and October 2010 (seven).
Three of Fulham’s four Premier League wins against City have come at the Etihad Stadium (2006, 2008 and 2009). However, they are winless in their last 18 against them in the league (D3 L15), losing each of the last 13 in a row.
City have won each of their last 16 meetings with Fulham in all competitions, the longest winning run one English league side has had against another in history.
OPTA WIN PROBABILITY
Man City - 72.6%
Fulham - 11.5%
Draw - 15.9%