Wilshere played 68 minutes for the Gunners' Under-21 side against West Bromwich Albion at The Hawthorns as he bids to make a comeback after 14 months out injured.
Frimpong also started the match and thinks that Wilshere can be pleased with an efficient performance.
He told the club's official website: "I'm happy for him to be back playing with the team again and to see a smile on his face. After 14 months out, he did very well and he can be pleased with his performance.
"When you've been out for so long, it's only natural you're going to be tired, he needs more games to get fit. I think the England and Arsenal fans should be excited to see him back again.
"He's probably my best friend at the club. It's only right because I've known him for 11 years. I'm just happy to be playing alongside him and I thought the team did well even though we lost the game, we can take some positives."
Frimpong was also getting some much-needed minutes in his first start since rupturing an anterior cruciate ligament on loan at Wolverhampton Wanderers in February.