Arsene Wenger insists Danny Welbeck did not suffer a recurrence of his recent injury despite coming off at half-time as Arsenal lost to Cologne.
The Gunners, showing 11 changes from Saturday's north London derby success over Tottenham, were beaten 1-0 in a poor contest at the RheinEnergieStadion.
Despite the defeat, however, Wenger's side still progress as Group H winners after group rivals Red Star Belgrade and BATE Borisov played out a goalless draw.
And there was more good news for Arsenal fans, as the Frenchman revealed the plan was always to withdraw Welbeck at the interval, having played his first game in a month following a groin injury.
"It was planned before the game that he would only play 45 minutes," he said.
"He has only just come back from injury, and we have three more games on Sunday, Wednesday and Saturday again.
"Medically, the risk was a bit too high to play him for longer because he has been out for a while. He has no problem.
"Of course, he was ready to stay on and frustrated to come off, but he's in good shape."
Wenger was not amused by the decision of Russian official Vladislav Bezborodov to award what turned out to be the match-winning penalty but did praise the hosts, who sit bottom of the Bundesliga without a league win all season, for their defensive resilience.
"We had a lot of possession," he added.
"We lost the game to one shot basically. It was a very nice penalty that we have to take on board. It was honestly not a penalty at all.
"We missed a little bit of the accuracy in our passing in the final third that is required to score more goals.
"We had plenty of dangerous situations but we always missed a little something to finish our chances.
"I must also say that Cologne defended with spirit, with commitment and overall the crowd was absolutely fantastic for them."