BBC Sport - Arsenal manager Mikel Arteta says it is "far from ideal" that Piero Hincapie and Martin Zubimendi were injured in a post-match training session after the Gunners' 2-1 Premier League win against Leeds.
A training session was held after Saturday's match at Emirates Stadium for players who either did not feature in or did not play the full 90 minutes against Leeds.
Ecuador defender Hincapie was carried off by goalkeeper Illan Meslier during the session, and Arteta later confirmed Spain midfielder Zubimendi was also hurt.
Hincapie, 24, came on after 82 minutes as Arsenal saw out victory against Leeds, while Zubimendi, 27, was an unused substitute.
"We had a training session planned after the match for everyone that didn't get enough minutes, and in two unfortunate actions we lost two players," Arteta said in a news conference before Tuesday's Champions League match against Lille.
"They'll have further scans to see where they are and we'll have that time frame for how long they are going to be out for."
When asked by the media what could have been done to prevent the injuries, Arteta joked the pair should not have trained.
"Never train and they don't get injured. The consequence of that is when you ask them to play they have no rhythm and no impact in the game," the Spaniard added.
"It's never happened in seven years I've been here. It could happen in the training session the next day.
"It's happened now and hopefully it doesn't happen again, but what can you do?
"If I had a crystal ball I would just say 'guys, get in the jacuzzi and I will see you tomorrow'."
Hincapie has made three Premier League appearances off the bench this season but started Arsenal's Champions League win over Napoli last month.
Zubimendi has also largely featured as a substitute, making five Premier League appearances from the bench.
How did the injuries happen?
Arsenal had planned for the players who did not play a full game or had not had minutes in the 2-1 win to train at the Emirates Stadium so that all of the squad could have a recovery day on Sunday and then train on Monday.
Arteta regularly arranges for the players who have not played a full match to take part in a small-sided game on the pitch, and this is how Hincapie and Zubimendi picked up the injuries.
The manager does this so that all of the players have a similar output when they are navigating their busy fixture schedule.
Arteta, who says it was done to get "everybody in the best rhythm", said Hincapie's ankle injury was more serious than Zubimendi's.
Substitute goalkeeper Meslier was seen carrying Hincapie off the pitch on his back, even though there were staff members present.
And this is something that Arteta does not seem to be happy about, saying: "that's something else, not to discuss here".