The Toffees host the Latics at Goodison Park in the quarter-finals on Saturday and Osman knows it will be no walk in the park if they want to progress to the final four after a 2-2 draw and a narrow 2-1 win over Roberto Martinez's men this season.
"The two games we have had against Wigan have been right up there with the toughest we have had this season. We have taken four points from the games but they haven't come easily and we know what to expect come Saturday," he told the club's official website.
"We have had a bit of a sticky patch for the last month. You find it hard to go through a whole season without having one of those. Hopefully now we have got a few players back, Kevin Mirallas is in form, so hopefully we can get back up and running.
"[But] it wasn't doom and gloom. We are still sixth in the league and in the quarter finals of the FA Cup, so it shows the high standards that a defeat or two - one of which was to Manchester United - is counted as a sticky patch.
"There has been a confidence about us pretty much all season. We came out of the blocks quickly and have been playing good football and believing in ourselves."