Wilshere has impressed for Bolton following his loan move from Arsenal in January and his eye-catching performance against Chelsea on Tuesday night was his eight successive Premier League game start.
Earlier in the week Coyle let it be known that if it were up to him, the 18-year-old would be joining the England squad this summer on the plane to South Africa.
The Wanderers boss feels Wilshere's maturity has shone through over the last few months, something that would set him in good stead should he get a call from Capello.
"It wouldn't faze him," Coyle said.
"I was asked a question and I answered honestly. People will perceive me as being biased because I work with him on a daily basis and I probably am, but for 18 years of age, he has maturity beyond his years and a great head on his shoulders.
"He is great on the ball, he can take opponents out of the game, he can give you a three-against-two or four-against-three situation. He sees a pass and he has got goals in him.
"He has continued to get better, he's really growing - not height-wise, but as a player.
"Whether Mr Capello feels he has done enough to get into his squad, then that remains to be seen, but I can understand why people would think he has a wildcard chance."
Asked whether the World Cup might come too soon for Wilshere, Coyle said: "If there is room for taking a young one or earmarking them for the future I don't know, but I certainly believe he is capable of playing with the best."
Wilshere's deal with Bolton runs out at the end of the season and while he admits his next aim is to break into the Arsene Wenger's first team, the youngster has not ruled out the possibility of spending more time at the Reebok Stadium.
"I'm sure it's something that the managers will discuss in the summer," Wilshere told the Bolton News.
"Obviously I'd rather stay and play at Arsenal, because I am an Arsenal player, but if it's not going to be that way then I don't see any reason why I wouldn't come back up here and play some more."
He continued: "I've had phone calls from the scouts at Arsenal. I'm sure the reports have been fine.
"Moving to Bolton has been good for me. I have got to play more in the Premier League, so that's been great.
"Things seem to come more naturally when you are playing more.
"The physical side of the game is important and it's been nice to learn that. Now, when I go back to Arsenal, I'll be that little bit stronger.
"That's the aim. I came here to get six months experience and then go back to see how things are. Hopefully I can break into the first team next season but we'll wait and see."
Coyle also praised the performance of Gary Cahill against Chelsea and suggested that both he and defensive partner Zat Knight may have given Capello food for thought at Stamford Bridge.
"I don't know if he (Cahill) is so much a late shout (for the World Cup) - he has been in and about the squad," Coyle said.
"Mr Capello was at the game the other night, where I thought both him and Zat Knight were terrific.
"We need those two playing at that level, and if they do, then who is to say that Mr Capello won't be looking at them?"