And a busy afternoon as far as roster transactions go continues, this time with the Texas Rangers making a few of their own. The team has designated right-handed pitcher Mark Hamburger for assignment, reports Jeff Wilson of the Fort Worth Star-Telegram, opening up a roster spot on the 40-man roster.

Hamburger, 25, has spent the season thus far pitching in the Pacific Coast League for the Rangers Triple-A team. The 25-year-old righty has posted an inflated 6.55 ERA across 45 1/3 innings of work down in Round Rock, with a 7.6 K/9 and 4.2 BB/9.

The team also placed first baseman Mitch Moreland on the disabled list because of a left hamstring strain, which opens up a spot on the 25-man roster. The man taking up both spots is no other than starting pitcher Roy Oswalt, who was officially called up from Triple-A today. He'll take his turn in the rotation tonight.