The nationwide lockdown came at the most inconvenient moment for the 26-year-old.
"It was frustrating because I was in good form," he told the official Chelsea website.
"I was getting a decent run in the side and things were going well, for the team as well because we were getting the results that we needed and we were kicking on.
"Since we've been back in training it seems we're back to where we were before. We're all looking forward to our first game on Sunday and hopefully we can continue where we left off."
Barkley, who could start on Sunday against Aston Villa, added: "We'll have to think back to when we were younger playing in the reserves or Under-23s. Sometimes at that level you play games at the training ground where there are only a couple of parents watching so it's going to be pretty similar to that. We just have to focus on getting the job done in every game that comes."