If all goes well he'll trek out on a rehab assignment and could rejoin the Rockies bullpen within a week. McGee had been pretty brutal before the injury, posting a 4.98 ERA in 21.2 innings. To make matters worse, he had only averaged 6.23 K/9, way down from his 11.57 mark just a season ago. He'll likely be placed back into the closer role for the Rockies, despite Carlos Estevez holding down the fort nicely in his stead.
Rosenthal has been brutal lately, so this isn't shocking news. He blew the save last night, and has allowed 11 runs in seven June innings with eight walks and 13 hits. Matheny will likely turn to Seung-hwan Oh to replace Rosenthal. Oh has been hailed as the Mariano Rivera of Korea, and has been excellent in his 38 innings with the Cardinals this season, with a 12.08 ERA, 1.89 BB/9, and sparkling 1.66 ERA. If you really want to hedge your bets you can also roster Kevin Siegrist who has also been quite good this season (2.79 ERA, 9.9 K/9) but is a lefty. If Oh does indeed inherit the closer's role, he may not relinquish it.
He's still recovering from elbow surgery, but this is exciting news. He'll still need some seasoning in the minors before he joins the Major League club, but could be with the White Sox sometime after the All-Star Break. His .300+ averages from his time with the Rockies aren't likely to recur since he won't have the bonus of playing half his games in Coors Field, but there's a chance he will be effective enough to be a corner infield option in deeper mixed leagues once he's in game shape.