By the Numbers: Moves of interest in the NL

As Cactus and Grapefruit League action comes to a close, we've already looked at the impact of the recent roster-shaping moves that have involved players in the American League. Now we move on to the National League, where we find a couple of third basemen who are unexpectedly sitting atop their respective teams' depth charts.

David Freese not only beat out Joe Mather for the Cardinals' third base job, but he could hold it for at least half the season. As Troy Glaus' recovery from arthroscopic shoulder surgery hits snag after snag, his replacement gets a chance to be a regular for an extended period of time. Freese has yet to play a major league game, but he held up well last season making the jump from High Class A to Triple-A. It would be no surprise to see Freese hit 20 home runs, though his 11:1 preseason K/BB ratio is indicative of a batting eye that needs to improve if he is going to hit for average. Even with a mediocre average, Freese falls somewhere in between Casey Blake and Bill Hall as a solid NL-only option.

Emilio Bonifacio is the Marlins' opening day third baseman. At the end of a bizarre string of decisions, from the demotion of Gaby Sanchez to the swapping of Dallas McPherson for Ross Gload, Bonifacio emerges as the everyday Fish at the hot corner. Some Marlins followers must have thought this was a April Fools gag, but there are some things to like about Bonifacio. His groundball tendencies along with a minor league track record of decent whiff rates could make for a batting average of .270 or higher, and he should be good for at least 20 steals. Best of all, he is eligible at second base. Ultimately, though, Bonifacio's utter lack of power still makes him a marginal NL-only player.

Huston Street grabs the closer's role in Colorado away from Manny Corpas. Coors Field still plays as a home run park, and flyballs are Street's greatest liability as a closer. He was able to get away with flyball rates of 40 percent and higher in Oakland, but in Denver, that could spell trouble for Street's ERA and save percentage. High flyball rates worked out well enough for Brian Fuentes and Taylor Buchholz last season, though both also posted unusually low HR/flyball rates. Fellow flyballer Luis Vizcaino, a fairly skilled reliever in his own right, didn't fare as well in Coors, as his 5.28 ERA attests. Street isn't a bad guy to have as a reserve reliever, and he should be fine to activate during Rockies' road trips, but exercise caution when he's pitching at home.

Franklin Morales wins the competition for the Rockies' final rotation spot. Going into 2008, expectation were high for Morales, who had pitched so well in his first eight major league starts that he earned a spot in the postseason rotation. His 3.43 ERA for the Rockies in '07 was too good to be true. Morales' .283 BABIP was too low for someone with a meager 26 percent flyball rate, and he somehow managed to find control after walking hordes of batters in High Class A and Double-A ball. He didn't do anything last season to make his '07 performance look any less fluky. Morales is nowhere close to being ready to make your rotation, even in an NL-only league.

The Pirates anoint Jeff Karstens as their No. 5 starter. Karstens had a nice little late-season run in Pittsburgh last year, giving his owners a 4.03 ERA and 1.34 WHIP in nine starts. When Karstens has success, as he did in '08, he owes it to low walk rates. This is not a pitcher to target if you need Ks, but Karstens can help your NL-only team with ERA and WHIP if he can limit the long ball. As a pitcher with some mild flyball tendencies, that's a little bit of a risk. There are worse pitchers for rounding out your NL-only roster -- Mike Hampton and Jason Marquis, to name two -- than Karstens.

Walter Silva is named the Padres' No. 3 starter. Silva's professional resume consists solely of seven seasons in the Mexican League, so it's hard to know exactly where to set our expectations for him. We do know that Silva is a groundball pitcher who has compiled some mediocre strikeout and walk rates. Over the last three seasons, he has yielded just 19 home runs in 326 innings (0.5 HR/9), so it would appear that Silva relies on minimizing homers to be effective. However, Mexico doesn't seem to be as hospitable to the long ball as the U.S. and Canada. Silva's HR/9 rate of 0.5 last season made him only the 19th best out of 51 pitchers who qualified in this category (according to data from minorleaguebaseball.com). So let's recap what we can surmise about Silva's skill set: not many strikeouts, too many walks, and a middling home run rate. You can afford to see how his first few starts go before fishing him out of the waiver pool.

Austin Kearns is still a National and could be the opening day right fielder. How Kearns is even in the same conversation with Elijah Dukes regarding a starting role is beyond me, but is Kearns worth rostering if the Nats make the counterintuitive choice here? It's seems like more than coincidence that Kearns has shown little power since leaving Great American Ball Park. His lowest Isolated Power at his old Cincy park was .189; his highest while playing in D.C. was the .179 mark he compiled in 63 games in '06. Kearns does not have the kind of power you want from a Fantasy outfielder, and he does not offer enough in terms of batting average or stolen bases to merit consideration, even in NL-only leagues.

Al Melchior was recently a Fantasy columnist and data analyst for Baseball HQ and will be providing advice columns for CBSSports.com. Click here to send him a question. Please put "Melchior" in the subject field.