Walker made his first senior start of the season at the Ataturk Olympic Stadium as Spurs went down 1-0 in their final Group C game.
The full-back played all but the final 14 minutes, having previously worked his way back from an abdominal injury by featuring in reserve games.
However, having returned to the first-team fold, England international Walker feels he has now regained match sharpness.
"First and foremost, we're all disappointed about the result but for me personally it was good to get back into the swing of things," he told the club's official website.
"I never hold back, I put 100 per cent into everything and tried to get forward when I could. Hopefully I can push on from here.
"I still feel a little rusty in my decision making but that will come with time.
"I've played 67 minutes, 90 and now 75 for the first team so by the next game, if selected, I'll be sharp and fully fit.
"Everything feels perfect and I’m ready to go again for Sunday."
