The midfielder featured in Saturday's 0-0 draw with former club Real Madrid.
He said, "I've spent several years working on fitness and the physical side of my game. At Real Sociedad, my game was more positional, waiting to receive the ball. At Betis, it's much looser. Now I feel much better, I still feel fresh on 90 minutes, I feel strong when I'm on the ball and I'm able to drop back and help the defence towards the end of the game. That's where I think I have made a big leap.
"We've been looking to find the ideal places for all of the team, adjusting things little by little so that we all feel comfortable. I struggled to enter play when I was playing out wide on the wing but since Fekir arrived, he likes to play in specific place. Now I have freedom to roam, I feel good physically so I can start and finish moves."