The St. Louis Cardinals' acquisition of right-handed starter Justin Masterson from the Cleveland Indians proves one thing: You can never have too much starting pitching. Remember back in spring training when the Cardinals had seven or eight viable candidates for the rotation?

Now, Jaime Garcia is out for the season; Michael Wacha is out until at least September due to his shoulder stress reaction; Shelby Miller has seen his strikeout rate plummet in his sophomore campaign; Joe Kelly has had two bad starts in three appearances since returning from a two-month stint on the DL.

The Cardinals do have the fifth-best rotation ERA in the majors despite all those issues, but they had enough concerns about the group behind Adam Wainwright and Lance Lynn to trade Double-A outfielder James Ramsey for Masterson.

It's a move for depth, not a move that gives the Cardinals a front-line guy. It's a hedge against Wacha not returning at all, or Carlos Martinez being shut down or moved back to the bullpen because of an innings limit, or Miller not figuring things out. Masterson, who has been on the DL himself since July 7 with right knee inflammation, will make his Cardinals debut on Saturday against the Brewers.

That's actually a key reason the Cardinals got Masterson: The Brewers have a right-handed-heavy lineup and Masterson has always been tough on right-handers, as he relies almost exclusively on a hard sinker and slider. Righties have hit .214 with one home run against him this season while lefties have banged him around for a .330/.416/.519 line. Masterson had his best season in 2013 in part because he held lefties to a .248 average, but the year before they hit .296 off him. Without a changeup or curve, he just lacks a good out pitch against southpaw swingers.

Anyway, Masterson has pitched better than his 5.51 ERA would indicate. His fielding independent pitching mark is 4.06 as he's maintained the higher strikeout rate he improved on during last season. Still, the velocity on his sinker, which he throws about 65 percent of the time, had dipped from 91.3 mph last year to 90.0 this season. That may be related to the knee problem, but probably factored into the Indians backing off from talking a long-term extension for the impending free agent.

One thing the Cardinals are banking on is improved infield defense to help the ground-ball specialist. The Indians have had one of the worst infield defenses in the majors with -39 defensive runs saved; the Cardinals have had one of the best, with +35 DRS.

While Masterson's ultimate performance is unpredictable, especially given his knee issue, he's probably not a big upgrade over what the Cardinals have received so far from their back-end guys. The risk for St. Louis was continuing to rely on Miller or Martinez; Masterson should at least provide a little more certainty than those two offered.

The Cardinals have three series remaining against the Brewers and three against the Reds, another team that leans to the right side (particularly with Joey Votto out). Two of those series are back-to-back, so Masterson won't necessarily get three starts against each team, but it gives Mike Matheny the opportunity to get Masterson the best possible matchups.

The Indians acquired Ramsey, a 24-year-old left-handed-hitting center fielder batting .300/.389/.527 at Springfield of the Texas League. He's not young for Double-A and is repeating the level as well, but he was a first-round pick (23rd overall) in 2012 out of Florida State, so has the first-round tools package and talent. Baseball America had Ramsey as the Cardinals' No. 7 prospect in its midseason update, so he projects as a possible major league starter due to his ability to play center.

I like the trade for both teams. The Cardinals acquired rotation depth -- yes, Jon Lester or David Price would have been nice, but considering the offense is next-to-last in the NL in runs scored, trading top prospect Oscar Taveras would have fixed one problem while creating a hole in next year's lineup -- while dealing from their depth of minor league outfielders. The Indians traded away a guy who has been inconsistent and would have been too expensive to sign while getting a guy who could start for them as soon as 2015.