Arsenal manager Arsene Wenger says he is reluctant to buy a new striker, despite a long-term injury to Olivier Giroud.
AC Milan have held talks with Chelsea over the transfer of Fernando Torres, according to Sky sources.
The Irish midfielder opted against several other suitors to become Coyle's first signing as new Latics boss.
McCann arrives on a free transfer having rejected a new deal at Burnley, where the pair worked together between 2007-1010.
The 25-year-old told Wigan's official website: "It's a massive club and as soon as the call came I was desperate to get over here and get things signed.
"I'm fully committed and hopefully I'll get to show what I'm capable of very soon. The people I've met around the place, you get the impression this is a friendly club, so I'm delighted to be and looking forward to the challenge.
"Owen was a big factor in the decision of course. Having worked with the gaffer at Burnley, and experiencing what he did with us there, I know he's a manager who'll spread confidence throughout the place and he's certainly someone I'm looking forward to working with once again.
"It was a difficult decision to come away from Burnley, but when you've been with a club for so long sometimes you feel as though you need a change. This it's a new challenge for me, and one I'm looking forward to, playing on domestic and foreign fronts during the season.
"We'll need a big squad and the gaffer has already mentioned bringing in quite a few new faces to add to the quality that is already at the club.
"So it's going to be a big season for us and hopefully we can succeed in all the competitions we take part in, but the main aim is promotion back to the Premier League."