The Rockies will call up left-hander Tyler Matzek to start Wednesday against the Braves. It will be his major league debut. The move is mostly out of necessity, as Jordan Lyles (hand) and Eddie Butler (shoulder) have both hit the disabled list over the past few days. Matzek, 23, has a 4.05 ERA and 61/31 K/BB ratio in 66 2/3 innings over 12 starts in Triple-A this season. He has impressed his control somewhat, but he's a risky play in fantasy leagues.