The American defender knows MacLean's credentials as Wednesday's star striker is on the line after he only played a handful of games for the club last season.
But Simek has been impressed with MacLean during pre-season and admits that he will be out to prove a point this year.
"Steve has been doing really well," Simek told Footymad. "He scored two goals against Rochester and he is looking very sharp. I haven't seen him play all that much to be honest since I have been at the club but seeing him play in America just shows you how much heart he has and what a good player he is."
This season though is all about progress for the former Arsenal defender but Simek admits with a bit of luck, The Owls will make massive improvements to their performance of the last campaign.
He added: "We have to look to move on from last season and improve. We didn't do badly last season
– we stayed in the division which was a great achievement when you put in to consideration the budget and the injuries we had. We have signed some good players though and hopefully we can get off to a good start and impress."I think we are not far off from being a really good team but we have to stay injury free and that is very important, we had terrible luck last year with injuries so if we can keep fit then I am sure we can put in a good season."
Wednesday's youngsters lost to Burton Albion 2-1 last night.