'Important day' for Sox as Kopech throws off mound

On the injured list since May 27 with a strained left hamstring, pitcher Michael Kopech threw off the mound Tuesday before the Sox played the Rays.

"Important day," manager Tony La Russa said. "What you do always is, whenever there's a next major test, you evaluate how he feels during it, afterward and tomorrow. May have some more certainty tomorrow but today's a big day because he is throwing."

Losing Kopech has been a double blow because he's been effective as a starter and reliever.

The 25-year-old righty is 1-0 with a 2.25 ERA in 3 spot starts and 1-0 with a 1.40 ERA in 11 appearances out of the bullpen.

"He's a major weapon but we have other weapons and we have to play with them," La Russa said. "So be very careful, take as much time as he needs because when he comes back we want him 100% so he can give us that lift. In the meantime, go with what you've got."