Fletcher is good friends with Wickham, having played alongside the centre forward at Sunderland.
Former Ipswich Town trainee Wickham impressed in the second of his two loan spells with the Owls, hitting eight goals in 11 matches before returning to the Stadium of Light.
Fletcher, recruited on a free-transfer by Wednesday a week ago after being shown the door by Sunderland, told The Star: “Connor came here on loan a few years ago and he had nothing but good things to say about the place.
“He actually dropped me a text the other day to say congratulations on the move.
“I’m a different kind of player to Connor but hopefully I can help the team build on what they did last year. That’s the plan.”
The move also sees Fletcher reunited with his international teammate Barry Bannan.
“It is always nice when you come to a new club and know a few people,” Fletcher conceded. “It just makes things a lot easier when you are settling in.
“I did speak to Baz [Bannan] before I came down and he gave me a little heads up over what it would be like.
“I had already made my mind up by then but I just spoke to Baz. He’s full of banter. We just had a laugh.
“I’ve known Baz [Bannan] for a long time. I’m good friends with him.
“Baz is a great lad and always the loudest in the changing room! I think that’s just the Scottish in him!
“He’s a great talent and he showed that last year by how well he did. He has said it himself that he wants to maintain that form this season. Every time we have played together at internationa level with Scotland, we have linked up well so hopefully we can take that understanding into this season.”
Fletcher, formerly of Hibernian, Burnley, Wolves, Sunderland and Marseille (loan), has trained with his new teammates for the first time this week.
He said: “The lads have made me feel very welcome and it has been good so far. I’ve really enjoyed the training sessions.
“The gaffer has already told us what he expects. He wants us to get the ball down and play and to give 100 per cent.
“I watched the team a few times last year and they like to get the ball down and play which suits my game. It has been good so far.”
This season will be the first time Fletcher has ever played in the Championship in his career. He admits Carlos Carvalhal played a big part in his decision to drop down a level.
“I spoke to him and he’s very enthusiastic for the way he wants the team to play,” he said. “Carlos said all the right things to me and I was happy about that. The way he likes to play football is the way I like to go about my business.”