Arsenal manager Mikel Arteta said he had never known a similar situation in his seven years at the club after Piero Hincapie and Martin Zubimendi were injured in a post-match training session after their Premier League win over Leeds United.

Hincapie, 24, came on in the 82nd minute as Arsenal won 2-1 against Leeds on Saturday, while Zubimendi, 27, was an unused substitute. Both players are now doubts for Arsenal's Champions League clash against Lille on Tuesday.

"It's never happened in seven years I've been here. It could happen in the training session the next day," Arteta told reporters on Monday.

"It's happened now and hopefully it doesn't happen again, but what can you do?"

The Spaniard said the pair were injured during an additional session arranged for players who did not get enough minutes against Leeds.

"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," he said.

"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."

Arteta said the extra work was necessary to ensure squad players were ready when called upon.

"If they never train, 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," he said.

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 league appearances from the bench this campaign.