Arsene Wenger’s men beat Urawa Red Diamonds 2-1 in their final game of their Asia tour and Wilshere felt their recent friendlies have been great preparation, especially personally after spending long spells on the sidelines through injury.
"I felt better and better every game," he told Arsenal Player. "It's difficult with the conditions. You struggle to catch your breath. The performances have got better every game and the opposition have got harder every game so it's good preparation.
"We've got the Emirates Cup coming up now and then Manchester City [in Helsinki] and then the season starts so we're going to be flying. I'm probably 80 percent fit. We've got a couple more tests and then we'll be ready."
Wenger has given many of his youngsters plenty of game time in the recent friendlies with Chuba Akpom, Gedion Zelalem, Serge Gnabry and Chuks Aneke all featuring and Wilshere has been impressed with their performances.
"I remember when I was their age," he added. "It's good to come away and get used to being around the first team and learning from the manager, who is good at bringing young players in and breaking them in slowly.
"They've done well and hopefully they can get in the Emirates Cup squad and really show the home crowd what they can do."
Meanwhile, Laurent Koscielny feels the club is full of confidence and in good shape ahead of its opening fixture against Aston Villa.
"We won all our games so that's good confidence," he told the club's official website. "We had a lot of training and all the players trained very well and gave themselves for the team.
"Preseason is very important for the Premier League. It's a long season so we need to be fit - I think we did well. The win gives us some confidence, and it's good for the next games - the Emirates Cup, [the friendly] against Manchester City and the start of the season."