Arsenal star Alexis Sanchez was dropped for Saturday's Liverpool game as a disciplinary measure after falling out with Arsene Wenger and storming out of a training session during the week, several British newspapers reported on Sunday.
Wenger surprisingly dropped Sanchez to the bench for the crucial clash at Anfield before bringing him on in the second half of the 3-1 loss, when the Gunners were already 2-0 down.
While Wenger said the decision was based on tactical reasons, newspaper reports Sunday evening said it was because the Arsenal boss had lost patience with the star striker's attitude in recent weeks. The Guardian and Telegraph both reported that Sanchez stormed out of a training session during the week and then clashed with teammates in the dressing room.
Sanchez's future at the club had already been in serious doubt as he has refused to sign a contract extension, and the fallout with Wenger only increases the likelihood of the Chilean leaving the club this summer.
It's the latest blow for the Gunners, which comes on the heels of big losses to Chelsea in the Premier League and Bayern Munich in the Champions League.
The 5-1 loss in Munich is said to have contributed to Sanchez becoming increasingly agitated with his teammates, and Wenger in turn becoming frustrated with the forward's attitude.
Sanchez is Arsenal's leading scorer this season with 17 goals and nine assists in the league, but has often let his frustrations show on the pitch after disappointing results.
Fellow star Mesut Ozil missed the Liverpool game with an illness, and the German's future is also in doubt as he is in the same contractual situation as Sanchez. Arsenal play Bayern in the second leg of their round-of-16 tie at the Emirates on Tuesday.