Popov insists he felt relaxed throughout his first Barclays Premier League fixture despite admitting to being frustrated by the full-time scoreline.
"It was good and I felt very comfortable when I ran out," he insisted to the WBA website.
"It was good to get 90 minutes of football as I haven't played since I played for my country a few weeks ago.
"I have had some small injuries and I only trained for four days before the game.
"Now I'm fit but I'm a little bit disappointment because we didn't win."