KANSAS CITY, Mo. -- Friday was a big day for David Robertson. For the first time since he went on the injured list last month, the Phillies’ most important relief pitcher picked up a ball here at Kauffman Stadium and lightly played catch.

With his right arm, that is.

Robertson’s left arm has gotten its usual workout recently. The 34-year-old is ambidextrous, if only when it comes to throwing a baseball. He can’t write or tie shoelaces with his left hand, but he is able to throw a ball upward of about 80 mph, though it’s been years since he kept track.

It’s a trick -- more like a learned skill, actually -- that Robertson picked up in high school and has messed around with throughout his 12 years in the majors. He gets such a kick out of it, in fact, that he asked Wilson to supply him with two gloves for his right hand that he keeps alongside the ones for his left that uses in a game.

But before anyone gets any bright ideas, such as Robertson’s joining the exceedingly short list of “switch pitchers” in baseball history, there’s even less chance of that happening than there is of Robertson’s hitting a home run this season -- and he has never gotten a plate appearance in his entire big-league career.

“I would love to, believe me,” Robertson said the other day. “I joke about it all the time. I say, ‘I would love to pitch left-handed.’ I don’t think I would ever be capable of throwing at this level. If anything, maybe I could get to the point where I could be good enough to just mop up innings instead of a position player pitching. But it would take a lot of work.”

More than, say, tossing balls from the outfield to a bucket behind second base every day during batting practice for the last 17 years or so?

"Oh yeah," Robertson said. "I can spin little curveballs and change-ups, and I can throw it to the bucket. Throwing it to the strike zone would be a whole other thing."

Robertson figures he has been a wannabe lefty since his sophomore year at Central-Tuscaloosa High in Alabama. He was dealing with shoulder fatigue -- his only other arm-related injury until his present condition, a flexor strain in his right forearm/elbow that has sidelined him since April 15 -- and was shut down from throwing for a few months. He wanted to play summer ball, though, so he took a turn as a designated hitter in American Legion games.

As a goof, and to fill the idle time, he decided to try to throw left-handed.

"I figured, well heck, if I can throw right-handed, why can't I throw left-handed?" Robertson said. "I just sort of tried to mimic the same thing I do with my right arm with my left arm. It kept me occupied, I guess."

Robertson kept working at it, especially once he stopped playing shortstop and became a full-time pitcher at the University of Alabama. He made a game of it during batting practice, grabbing a right-handed glove, shagging fly balls in batting practice, and heaving them in left-handed.

Over the years, Robertson has found that he isn’t alone. Several other pitchers do the same thing, including former Phillies right-hander Freddy Garcia. Chicago Cubs righty Yu Darvish goes so far as to throw left-handed long toss as part of his training routine.

Phillies right-hander Vince Velasquez was a lefty-throwing center fielder for one year in high school because he had bone spurs in his right elbow. After taking a 96-mph line drive off his right arm in a game last season, he fired a left-handed strike to first base to retire the batter.

David Robertson signs autographs with only his right hand. But the Phillies reliever can throw a baseball with both hands.
JOSE F. MORENO / Staff Photographer
David Robertson signs autographs with only his right hand. But the Phillies reliever can throw a baseball with both hands.

And then there’s Pat Venditte, who takes switch pitching to the next level. Naturally right-handed, Venditte began throwing with his left hand even before he was old enough for Little League and got so adept at it that he reached the big leagues by throwing with both hands in games.

Venditte, recently designated for assignment by the Giants, spent the 2017 season in triple A with the Phillies. Robertson got to know him from their days in the Yankees organization. Venditte was actually the second switch-pitcher whom Robertson saw. He played against an ambidextrous pitcher in high school but lost track of him after that.

Robertson was so intrigued by the six-fingered glove custom-made by Mizuno that enables Venditte to easily switch back and forth that he asked if he could keep one.

“I still have it in the house,” Robertson said. “I’ve used it occasionally. It’s not my company, so I really can’t. Wilson told me that they had one and they might be sending me one. Hopefully I can get one.”

If Robertson had started throwing left-handed at a younger age, could he have been another Venditte?

"Maybe," he said. "I think the big thing is you just have to realize you're going to be very bad at it when you start and then over time you get better. If I actually worked on it, I think I'd be much better at it."

The thought has occurred to Robertson over the last few weeks. He’s on the injured list for only the third time in his career and the first time with an arm injury. He has never needed to throw left-handed because his right arm has always been healthy.

“I was hoping to be back really quick. It just didn’t work out that way,” said Robertson, who must now go through what figures to be a lengthy throwing progression and isn’t likely to return until next month.

“I’m a little frustrated with it. But you’ve got to do what’s right. I don’t want to end up going backward. When I get going, I want to be ready to go.”

Until then, he’ll always have those left-handed throws in batting practice.