By Tommy Rancel //

Through a series of moves over the past two seasons, the Philadelphia Phillies have put together what is known as the “four aces” rotation. After acquiring Roy Halladay and Roy Oswalt last season to join their own ace in Cole Hamels, they signed Cliff Lee this offseason to complete the quartet. Thus far, three of the aces have lived up to the hype. Hamels, Halladay, and Lee have been fantastic in 2011. Oswalt, on the other hand, has battled injuries – including a back injury that could jeopardize his career. With an ace down, the Phillies have pulled out a wildcard in 23-year-old Vance Worley.

Worley tossed seven shutout innings on Monday against the Florida Marlins to run his record to 4-1 in 10 appearances (eight starts) this season. He has made 10 career starts (15 appearances) with a 2.03 ERA in 62 innings. This includes a stellar 2.29 ERA in 49 innings this season. On the surface, Worley is performing like a fourth ace, but buyer beware on the youngster.

In deep leagues and NL-formats, Worley is a good pickup. Considering the health of both Oswalt and fellow injured starter Joe Blanton, Worley is likely to rack up a starts from now until season’s end. In a deep league, the counting stats alone are worth the pickup. Meanwhile, the righty offers little in terms of peripheral statistics and his ERA almost certainly will rise with a larger sample size.

A groundball pitcher, Worley, has done a good job of covering balls in play into outs. This is also a byproduct of defense, but in general, keeping the ball on the ground is a good thing because it can be easily converted in to an out. Groundballs are also good because they can never go over the wall for a home run. Despite pitching in a hitter-friendly environment, Worley has surrendered just three home runs in his big league career.

While he could be an outlier in terms of a lower than normal batting average on balls in play (BABIP) and home run-to-flyball rate (HR/FB) conventional wisdom says Worley will fall back to the pack at some point. Because he is so young and does not have an established history, we don’t know where that will be; however, considering his stuff (upper-80s/low-90s), peripherals (1.85 strikeout to walk rate) and his ballpark, his current marks of .259 BABIP and 3.6% HR/FB are not likely to continue even if he blossoms into the fifth ace down the road.

If you have Worley in a standard 10-12 team mixed league, now would be the time to sell. Consider using Worley as part of a package that could net you a more proven starter who has traditional stats that may not be up to par. For example, David Price’s ERA is nearly a full run higher than it was last season. That said, he continues to rack up strikeouts as a good rate, has drastically reduced his walks and does not give up a ton of home runs. Also consider, Tropicana Field has turned in to the East Coast version of Petco Park. If Worley and a decent position player can nab you a true ace like Price, do it now.

For more on Worley and other young arms, check out Bloomberg Sports Front Office.