The 23-year-old Hayes has 39 points, including 22 goals and 17 assists, in 58 games for the IceHogs this season. He had a hat trick and two assists on March 9. He had five goals and four assists in 31 games for the Blackhawks last season.
Montador cleared waivers on Tuesday, a source told ESPN.com's Pierre LeBrun. Montador hasn't played in a game since March 27 and recently was activated.
Montador missed time on two occasions because of head injuries last season. He had five goals, nine assists and a plus-4 rating in 52 games last season.
The Blackhawk are 21-2-3 with an NHL-best 45 points this season. They play the Columbus Blue Jackets on the road Thursday.