Typically, velocity comes back first.
For pitchers rehabbing from Tommy John surgery, this is a function of weeks spent on exercises designed to strengthen their throwing arms. Once the process is complete, many return to the big leagues with the kind of radar gun readings they had before going under the knife. Regaining velocity can happen relatively quickly.
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Regaining full command, however, is often a different matter.
This is not lost upon either Matt Harvey or Jeremy Hefner, the Mets righthanders who are nearing a major step in their recovery from Tommy John surgery.
The incline of a pitcher's mound adds to the strain of throwing a baseball. Pitchers coming back from Tommy John will go months without the added challenge of gravity. But according to pitching coach Dan Warthen, both Harvey and Hefner could be back on a practice mound as early as the first week of June.
"I'm pretty amazed at both of them," Warthen said this week.
When Hefner joined the Mets earlier this month in Miami, Warthen said he was "surprised at how hard the ball's coming out of his hand."
The pitching coach was even more bullish on Harvey, who "looks like he can pitch now, that's how firm the ball is coming out."
Both have a shot at returning to the Mets before the end of the season.
To build arm strength, both Harvey and Hefner have been in a long-toss program, with each progressing to 120 feet. By next week, Warthen said the plan is to push both pitchers to 150 feet. Following that comes a return to the pitcher's mound.
The final step is pitching in a game.
Once there, command will be foremost on the minds of Harvey and Hefner. As it should be. Command turned the 25-year-old Harvey from a promising prospect to the National League starter in last year's All-Star Game. Command turned the 28-year-old Hefner from a minor-league depth piece into a major-league starter.
And it will likely be command that ultimately determines whether Harvey or Hefner will bounce back smoothly.
"I've got to get it quick, not only with my fastball but with my off-speed pitches, as well," said Hefner, who was 4-8 with a 4.34 ERA in 2013 before an elbow injury ended his season. "It's such a big part of what I do, keeping guys off balance."
Long-tossing sessions are mostly tedious affairs, far from the spotlight of big-league games. But for Harvey and Hefner, improving upon command is as simple as using their throwing sessions to lock in on a target, and hitting them over and over again. Harvey aims for his throwing partner's chest. Hefner prefers the face.
For now, this is the best the pitchers can do to stay sharp, in hopes that it eases their eventual transitions back to game action.
"I'm a big believer in that every time you pick up a baseball, you have a purpose, you have a plan, and that transfers over to the stuff you do on the field," said Harvey, who was 9-5 with a 2.27 ERA when he was injured last season. "If I start now, and not push velocity as much as I push location and effectiveness now, once I do have the opportunity to come back, it's still there."