Look, guys...having cap space doesn't mean that every single trade proposal we make needs to have us retaining money. Retention alone is worth extra from the team that's getting the player.
Mantha is on a good contract by any standard in the league. Somewhere between what a 1st and 2nd liner gets around the league. And if he were to be traded now it isn't instantly 5.8 million against a team's cap. it's pro rated based on the number of days left in the season.
Next year Mantha will be a full 5.8 million against another team's cap, but you know what? That's their problem. Next year.
Any trade involving Mantha should not have any retention at all.
Here are a few trades that may be a good barometer for what Mantha would get us in return:
2019: Kevin Hayes from NYR to Philadelphia for 1st round pick, Brendan Lemieux and a conditional 4th.
2019: Mark Stone from OTT to Vegas for Erik Brannstrom, Oscar Lindberg and a 2nd round pick.
2020: Barclay Goodrow and a 3rd round pick from SJS to TBL for Anthony Greco and a 1st round pick
2020: JG Pageau to NYI from OTT for conditional 1st, conditional 2nd, and conditional 3rd.
2020: Blake Coleman to TBL from NJD for Nolan Foote and conditional 1st round pick
Just because Mantha is having a down year it doesn't mean he's all the sudden worth a 4th rounder unless we retain the dude's salary. He'd easily fetch us a similar package to any of the above. (Also I can't believe how cheap Mark Stone went. f***, we could have had him for Cholowski, Dominic Turgeon and a 2nd? Sign me up for that!)