"We've talked pretty consistently about his rhythm, where there are some times he's just jumping off the mound because he feels so good and can throw 100 [mph] and wants to show it," manager Mike Matheny said. "He doesn't quite need 100."
Martinez, who made one spot start in the Majors prior to this season, threw a career-high six innings on Tuesday, allowing four runs on nine hits in an eventual 5-4 win over the Pirates.
He did use his fastball -- he got All-Star Andrew McCutchen to swing through a 99-mph heater in the first inning as one of six strikeouts -- but made it through six innings by focusing on more than velocity, including what Matheny called Martinez's best sinker and quality offspeed pitches.
"I'm seeing more of a variety of pitches," Matheny said. "There is that first at-bat with McCutchen where he is just rearing back and letting it [go]. He's got that kind of ability. But then he backed off and he took a little off breaking balls at times. For the most part, he was better in the strike zone today, and he was rewarded by going deeper."
Martinez's trouble came when he left two pitches over the zone, resulting in a pair of two-run homers. He exited after having thrown 85 pitches.
With Martinez considered a long-term member of the rotation, the focus is on moving him away from relying solely on short bursts of high velocity and instead on pitching deeper into games.
The Cardinals, with Tuesday's win, improved to 5-0 when Martinez starts.
"I felt really good tonight. I felt I was consistent with my pitches," Martinez said through bullpen catcher Roberto Espinoza. "I think I just need to pitch."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. Alex Halsted is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.