Lionel Messi has claimed that it was "hard starting again" after returning from a two-month lay-off to start Tuesday's Champions League Group A match against Roma.

Messi had been out of action for Barcelona since September with a knee injury, but came off the bench in El Clasico at the weekend, before being named in the starting XI against Roma.

The Argentine scored twice in his team's 6-1 win, in addition to providing one assist, but he has said that it was difficult to find match rhythm after a period on the sidelines.

"I'm happy with the game, the result, playing 90 minutes again. I'm returning little by little and luckily it's all going well," Messi told AS.

"It has been hard starting again. I prepared well and trained but it's not the same to train as to go onto the pitch and play for 90 minutes. I'll get back up to speed calmly."

Barcelona's thumping win against Roma saw the Catalan side breeze into the knockout stage of the Champions League.