"He's one of those guys that's going to eat innings and keep you in ballgames regardless, and the type of guy who's fearless," said catcher John Buck, who spent time with Marcum in Toronto in 2010. "He doesn't care who you are, he doesn't care that he happens to throw 87, 88. He throws off his changeup, he changes speeds and he'll throw any pitch, any time, any count, in or out. You have to adjust. That's what makes him effective."
In contrast, what makes some of the Mets' young arms effective is not only their arsenal but a top-notch fastball. In his rookie year last season, Matt Harvey lived at around 95 mph and often above it, according to FanGraphs' Pitch f/x. Jon Niese's and Dillon Gee's fastballs topped out around 93 and 94. Marcum never touched 90.
"They're all different pitchers," manager Terry Collins said. "One thing Shaun does, he doesn't overthrow. He stays within himself. Obviously, command is the most important part of pitching. And if they learn one thing, some of these guys that have great arms can say, 'Here's a guy, and I throw 10 mph harder than he does, and he gets easy outs. Maybe if I do that, I can get easy outs.'"
Marcum, 31, went 7-4 with a 3.70 ERA in 21 starts for the Brewers last season, and struck out 109 hitters while walking 41 in 124 innings. He missed more than two months of the season with tightness in his elbow following a bout of discomfort in his shoulder that sidelined him during Spring Training. He underwent Tommy John surgery in 2008.
So he knows now, perhaps more so than ever, that his mechanics and delivery are of the utmost importance. He's relying on his changeup and curveball in addition to locating his fastball.
When he rushes his delivery, his arm won't catch up to his motion and the ball will stay up in the zone. And at his velocity, that means trouble.
"Guys, when they start to struggle, they fight their mechanics," Marcum said after exiting Sunday's game against the Cardinals, a 3-0 win. "I've got to keep repeating my delivery, make sure I stay back on my back side and ride it out. I did that, for the most part, today."
Marcum was at his best on Sunday, striking out two in 3 2/3 innings of shutout work. He allowed just one baserunner -- outfielder Shane Robinson hit a ground-rule double with two outs in the bottom of the second -- and just four balls left the infield.
"His location is tremendous," Collins said. "That's his trademark, and he showed that today. He made pitch after pitch where he wanted to throw it. Really pitched well."
Marcum is pleased with his mechanics at this juncture of the spring, though he feels he has a long way to go, and he hopes to build his pitch count to around 100 by the time the Mets open the season. Now it's just about repeating the proper mechanics and, of course, pinpointing his location.
"It lets him show that it's not all about velocity," Buck said. "He'll be the first to tell you, it's about manipulating and locating. If our power pitchers can kind of get that and also have the weapon of making mistakes and still having guys miss because they throw that hard and are that sharp, and learn that from Marcum, then that just makes them all that much better."