We've spoken about the offensive upgrades made by the Mariners and how the "wild card" to it all is how much of an impact moving the Safeco Field fences in will have on the team.

But all of that could be offset by a decline in the pitching staff if the Mariners don't do something significant to upgrade their starting rotation. Moving in the fences will help the offense, in theory, yes. But using the same logic, it could also hurt the pitching staff even if you put the same five-man rotation out there as we saw for most of last year.

Now, of course, the Mariners won't have the same starting five as last year. In order to acquire Kendrys Morales, the Mariners had to trade away Jason Vargas. And they also saw free agent Kevin Millwood leave.

You didn't have to be a huge fan of either Vargas or Millwood. But between the two of them, they threw 378 1/3 innings last season and kept their teams in the game for the most part. Both pitchers relied heavily on their defense and — especially with Vargas — a pitcher-friendly home park , but they still were able to keep the score close after six or seven innings.

And you can't just let that walk out the door without replacing it.