We're going round the houses a bit here - the reality is a blurring of lines thanks to various formations that deploy wingers in different ways, and confusion over how broadly you define the unhelpfully vague word "forward". (Some people see it and think only of strikers - or strikers' arseholes - while others use it to describe all attacking players.) In the old days of 2-3-5 and then 4-4-2 it was clear what a winger's position was, but now there are variations that can mean a winger might be a wide midfielder with plenty of defensive responsibility or he might be effectively part of a three-man forward line. If you look at how Wigan lined up in that final, it's a case in point: Mcmanaman was very much their second most advanced player on the pitch. http://www.zonalmarking.net/2013/05...stifle-city-and-attack-with-tremendous-width/ So you could certainly make a case that he was playing as a "forward" - but on the other hand he was out wide on the right. For me, the best way of avoiding this confusion is simply not to use the word "forward". It has so many different implications that it just causes trouble.
It's why I think these days players who are exclusively midfielders are labelled as such, while those who can play forward in a front three or two are generally also labeled as forwards.