Jake McGee was traded from the Rays to the Rockies in a head-scratcher of a deal that sent outfielder Corey Dickerson to Tampa. Dickerson had hit reasonably well in Colorado, and it didn't seem as if McGee would mean that much to the Rockies, who weren't (and aren't) expected to contend this year.
There was speculation that the Rockies were acquiring McGee so they could deal him sometime in the middle of 2016. Meanwhile, Dickerson is having an awful year in Tampa (.197/.244/.435), so the trade could wind up a big win for Colorado.
McGee has a 3.66 ERA and 1.525 WHIP in 21 games for the Rockies so far this year. He's been serving as their closer and has 14 saves (and two blown saves, one of which accounts for five of the eight runs he's allowed this year). As is the case for many Rockies pitchers, the real story of his effectiveness can be told in his home/road splits:
Home: 11 games, 10 innings, 5.40 ERA
Road: 10 games, 9⅔ innings, 1.86 ERA
Small sample size and all, but McGee was an effective middle reliever/LOOGY/closer for the Rays for several seasons (2.77 ERA, 1.017 WHIP in 297 relief appearances). He's making $4.8 million this year and is arbitration-eligible in 2017, so he'd come much cheaper financially (and probably in terms of prospects) than Miller would.
Oh, and there's that Rays connection. McGee pitched for Joe Maddon for five seasons in Tampa (2010-14), so Joe certainly knows him well, and it's quite clear that Maddon likes having players in Chicago who he has managed before.
So -- your turn. Good idea? I'd definitely explore acquiring McGee if I'm in the Cubs front office.