The two trades that brought Livan Hernandez to the squad last season, and Doug Davis this offseason, have prepared the D'Backs for this sort of scenario. The type of scenario that allows you to go out and get a veteran lefty with a ton of postseason experience and a track record of only spending part of the season on the active roster. In Mark Mulder's defense he has spent the majority of his career being healthy, until last season when he needed surgery. In David Wells defense, when they call it 'lite beer' they really do make it sound like it's part of the South Beach Diet, and its not.
But between Hernandez, Davis, and Brandon Webb, the D'Backs have three guys who are going to give them 30+ starts and 200 innings. They have guys who are going to, on most days, give the bullpen a night off. They also have a series of talented young pitchers like Micah Owings, Dustin Nippert, Edgar and Enrique Gonzalez (no relation) who are probably ready to take on at least a partial season of work in the bigs. Adding a Mulder or Wells is not about 35 starts, 200 innings, and 18 wins. It's about 15 very good starts, 100 very good innings, and veteran playoff chase tested arms in September.
It's a great situation to be in, and Josh Byrnes has to know that. Between the four previously mentioned youngsters, you are hoping that two step up at one point in time or another and claim the #5 spot in the rotation. It doesn't have to be one guy from the get-go either. Say Nippert comes out strong in Spring Training. His curveball is sharp, and he locates his fastball early on. Presto! He's your #4 (if we sign Mulder, who will not be ready for opening day) or #5 (if we sign Wells and he is ready for opening day). Now Nippert pitches well all through April and Edgar and Enrique torch the Pacific Coast League during the first month. Great, because when Nippert starts to struggle in May (after teams get their first live scouting reports on him for '07) you dip down into the Tucson rotation and pick the hot hand.
Either scenario allows the D'Backs to get good, long looks at their young pitchers, but in both scenarios as the pressure mounts and the playoff chase begins, you've got a veteran lefty who hasn't thrown a lot of innings ready to take the ball in September on the road in Dodgers stadium, or in late August on the road in San Francisco. If Micah Owings continues to simply win, sure, you can give him the ball, but you are not forced to.
The biggest thing though, is that regardless of what combination you end up with, you are not running your bullpen out there for seven innings of work five days in a row. It's one thing to ask your middle relievers to come in and give you three solid innings on Tuesday and Saturday. It's very different when the club's day off is also the bullpen's day off, and the D'Backs have done a great job at making the former a reality, and the latter a thing of the Brenly-esque past.