Matzek (elbow) began a rehab assignment at Triple-A Sacramento last week and has given up two runs (one earned) on one hit and one walk while striking out a batter across two innings over his two appearances.

Matzek had resided on Atlanta's injured list since early May while recovering from elbow inflammation before he was dealt to San Francisco on July 29. The left-hander completed his throwing progression shortly after joining his new organization and is now in the midst of a rehab assignment that could be extended into September if the Giants aren't satisfied with his results at Sacramento. He's scheduled to make his next appearance for the Triple-A club Tuesday, according to MLB.com.