Martinez was speaking ahead of the Yorkshire side's visit to the Liberty Stadium tomorrow although they come into South Wales four places behind their opponents.
Wednesday have yet to hit any of the heights they managed in the opening years of the Premiership when they rubbed shoulders with the game's elite in this country and reached both domestic cup finals in 1993.
A spell in League One (as is now) has come around in the last 10 years and Wednesday are no longer seen generally as a side who could challenge for promotion but that is not the view of the Swansea manager who told the Evening Post "They are a club who I think will slowly get back into the Premier League
"I don't know how long it will take, but Brian Laws is putting something together and they have a lot of players who know how to win games at this level.
"For us Sheffield Wednesday is another kind of challenge.
"We have shown we can be ourselves in this division at home and we've shown we can go away and be competitive. Now we will see if we can be ourselves against opposition who are not that far from being a top-flight club."
This article first appeared on JACKARMY.net.