RobertsonHead.jpgThe Tigers announced — on Twitter, no less — that they’ve traded Nate Robertson to the Marlins for minor-league left hander Jay Voss. Nate will become the only lefty in the Marlins starting rotation. He was set to start tomorrow in the Grapefruit League finale against the Pirates.

According to MLB.com’s Joe Frisaro:

Before being finalized on Tuesday, the Robertson deal first had to receive the approval of the commissioner’s office, because more than $1 million was being exchanged.

At $10 million this year, Robertson immediately becomes the Marlins’ highest-paid player.

For the Tigers’ rotation, it means that Dontrelle Willis and Jeremy Bonderman, both of whom are making final tune-up starts today, are the fourth and fifth starters — but not necessarily in that order. And that Eddie Bonine, another member of the Opening Day roster, will be Jim Leyland‘s safety net should either falter.

As for Voss, well, Frisaro tagged him as a “prospect” but he must not be a highly regarded one. In this piece on the Marlins’ top 10 prospects Voss is nowhere to be found. But the Freep‘s John Lowe reports:

Voss, 22, split the 2009 season between Class A Jupiter and Double-A Jacksonville. In 10 games with Jupiter, he compiled a 2.03 ERA and 10 strikeouts. Voss had a 3-0 record, 2.97 ERA and 36 strikeouts in 30 appearances with Jacksonville.

Selected by the Marlins in the eighth round of the 2007 draft, Voss saw action in 11 games with Mesa in the Arizona Fall League following last season. He fanned 12 batters in posting a 1-0 record and 4.91 ERA.

What cannot be minimized is Willis’ resurgence. If four weeks ago you had to guess which lefty had the best chance to make the Tigers rotation, you would’ve selected Robertson, right? I would have. And only because he was building on a strong finish to the 2009 season.

And, while Nate was having a nice, if not overwhelming spring, everyone was busy tip-toeing around the subject of D-Train. Sure, they were quick to point out his solid statistical spring camp but it seemed like the club was giving Willis a dignified exit from the organization.

Bottom line? The Tigers were going to get bubkus in a trade for Dontrelle Willis so they moved the most marketable major-league pitcher they had. In that regard, this trade makes sense.

Of course, now the question is: Will the 2010 model of the D-Train be a local or an express?