Mathieson designated. Why? It's complicated

Ready for a lesson in the convoluted rules of baseball's roster system?

The Phillies designated Scott Mathieson for assignment today to clear a spot for catcher Dane Sardinha. Sardinha is here because Carlos Ruiz is still a little woozy from getting his bell rung by a broken bat, but isn't hurt enough to require a stint on the 15-day disabled list.

So the Phillies needed a spot. Mathieson was the guy to go, for a quirky reason.

"He's sort of in limbo right now," Phillies assistant GM Scott Proefrock said.

He's in limbo because of a odd roster rule rarely used. Mathieson has options remaining. So many are asking, why designate him for assignment and expose him to waivers when he could have just been optioned?

Problem is, Mathieson cannot be optioned without going on waivers. Here is my understanding of Mathieson's situation:

There are four types of waivers, the rarest being optional waivers. They are required when a team wishes to option a player who has options remaining but is more than three calendar years removed from his major-league debut. Mathieson falls under that category; he made his debut on June 17, 2006. And he has options left.

"We still have the ability to option him, we just haven't done it yet," Proefrock said.

So the Phillies had to place Mathieson on waivers regardless. Will they lose him? Almost certainly no. Optional waivers are revocable, which means if a team puts a claim in for Mathieson, the Phillies can pull him back.

"We're very hopeful he stays in the organization," Proefrock said. "That's what our plan for him is."

There. So relax about Mathieson, he won't be going anywhere. And this concludes your baseball roster rules lesson. Pop quiz on Tuesday.