PHOENIX -- Arizona left-hander Randy Johnson will miss his next start Friday with tendinitis in his forearm.
Manager Bob Melvin said there is no plan for the 43-year-old Johnson to go on the disabled list.
"It's just a forearm thing that tightened up on him, so we're going to try to be proactive," Melvin said.
Johnson, who had back surgery last October, pitched 5 2/3 innings in a 5-2 victory at Pittsburgh on Sunday, allowing two runs and seven hits and striking out a season-high 10. He has won his last two starts.
Melvin said Johnson reported tightness in his forearm after the club returned to Phoenix.
"It was kind of an odd deal that popped up," Melvin said. "We thought it might be something that went away."
Right-hander Edgar Gonzalez, who is 1-2 with a 4.81 ERA, is expected to take Johnson's spot against Houston.