Some depth options

The Blues do not tend to like small centers unless they're blazers, and usually not even then. Voit is tiiiiny and at best an average skater.

Voit is a winger, but fair..
Maybe Holmberg could be moved instead.
You'd have to adjust the picks though as Holbergs value is much greater than Voit

The Leafs may project Voit as a winger, but he's a natural C and has played C at least as often as wing thus far. Either way, he's a reeeeeally small guy who doesn;t skate as well as he needs to.

And yeah, Holmberg would get you more than Voit with the Blues, but these picks are already light because the 2nd is pushed to 24. Maybe both 23 3rds and Holmgren does the trick, though.