Mikel Arteta revealed Ezri Konsa had "some issues" that forced him to come off in Arsenal's 2-1 win over Slavia Prague in the Champions League.
The Gunners moved up to third in the league-phase standings despite a sloppy second-half display that allowed their hosts back into the match.
Konsa Substitution Explained
Konsa started alongside Gabriel, though his place in the side is under increasing pressure with William Saliba back in the matchday squad for the first time this season.
In the first half, Konsa was seen feeling his knee. He continued after the break and was booked early in the second period before Arteta brought the centre-half off on the hour mark.
The Arsenal manager confirmed that was fitness related rather than a tactical decision.
"Obviously he's playing a lot," Arteta said. "He's played so many games in the last few weeks. He had some issues and we decided to take him off."
Rice Plays Full 90 Minutes
Arteta made six changes to his starting lineup in Prague, with Martin Odegaard, Riccardo Calafiori and Bruno Guimaraes among those to drop out of the side.
However, Declan Rice was not rested and he played the full 90 minutes, as Guimaraes and Myles Lewis-Skelly remained unused substitutes.
At times in the second half Rice looked exhausted, particularly after one driving run up the pitch late in the match.
Asked why he did not substitute Rice and afford him some rest, Arteta replied: "The game required [it] and he did it. He was as well rested against Fleetwood. He had a very good week to recover. It's the second [match in a row] that he's played, not the fifth one."
"We expect our players to be able to do that and I think he had some very good moments throughout the game."
