Centre forward Fletcher and goalkeeper Keiren Westwood are in contention to return to the starting line-up for the Owls’ home tussle with Ipswich Town today.
Although he has bagged three goals since moving to Hillsborough, it has has been a stop-start campaign for Fletcher.
Bannan, who, along with Fletcher, has been selected in the Scotland squad for their World Cup qualifier with England next week, told The Star: “Fletch is a massive part of the team and obviously he has been brilliant for us this season.
“He would probably have liked to have scored more goals but injuries and stuff have happened at the wrong time when he has been on a good run.
“I think he will comeback stronger from this and I have no doubt that he will score the goals that we need to get up the league.”
Fletcher could start after recovering from a head injury he sustained as a substitute in last week’s loss at Derby County.
It is the second time during the 2016/17 season Fletcher has suffered a head wound. Like on the opening day against Aston Villa, the former Sunderland striker’s knock required several stitches.
Bannan quipped: “I think this was just a little scratch compared to the last few he’s had! I think he’s had about 18 stitches over the season!
“I have told him to stop heading the ball or I think he’s going to get more!
“Fletch is a tough lad and is always going to get things like that with the way he plays. He puts his head in where it hurts. It is good to see that but I think he would think different!”
Bannan expects Ipswich to provide Wednesday with a stern examination of their promotion credentials but is confident they can make home advantage count.
He said: “It will be tough and Mick McCarthy has done a great job since going in there. You know what you are going to get from his teams. They are tough teams to break down and they will come with a gameplan. Hopefully we can make the home advantage count and get the three points on Saturday.”