TinCaps left-hander Nick Margevicius spent the offseason refining his curveball, hoping a third offering to complement his already solid fastball and changeup would help him become a more complete pitcher.

“I'm gonna rely on all three (pitches),” Margevicius said before the season began. “I think (the breaking ball) is a really good pitch for me now and I'm looking forward to seeing what it will do in the regular season.”

It turns out that the starter's optimism was warranted.

Margevicius has spent the season baffling hitters with well-placed low-90s fastballs and a sharp-breaking curveball that has become an out pitch for him. That combination has elevated him into the ranks of the elite pitchers in the Midwest League and he was one of four TinCaps named an All-Star on June 6.

“The challenge for him was he was basically a fastball-changeup guy last year,” said Sam Geaney, the Padres' director of player development. “He had a really, really good changeup, but we made it a priority with him and he went out in the offseason and found a curveball that's a real pitch for him and potentially a real quality major-league offering.

“Those things don't happen by accident. It's a credit to him that he showed the aptitude in developing it.”

Margevicius' new three-pitch mix has helped place him near the top of the Midwest League in several key categories. His 3.09 ERA is tied for eighth in the league, despite a couple of rocky starts, and he ranks fourth on the circuit with 76 strikeouts.

It's not simply that Margevicius has developed a hard-breaking curveball, however. He's also been able to command it remarkably well considering it's the first season he's really deployed it in game situations. One of his goals before the season was to get a strikeout with the curve against a lefty on a full count and he's done that multiple times.

In fact, the 2017 seventh-round pick has commanded all three of his pitches with precision for most of the season. That's especially true with his fastball, a pitch that, despite lacking dominant velocity, has been effective because he's been able to place it almost anywhere he wants in any count.

Margevicius has walked just nine hitters all season, five of which came in one start in late April. The lefty's 8.44 strikeout/walk ratio is easily the best in the Midwest League, but his fastball command has been so good that it actually presents a dilemma.

“(I need) to throw more offspeed pitches,” he said. “I can kind of throw a lot of fastballs right now because of how I'm commanding it really, but I think to succeed at higher levels, I'm gonna have to throw those offspeed pitches more and more when I'm behind in counts, so I'm gonna have to start working on that now.”

Such a diagnosis represents a commitment to process over results and hints at another aspect of Margevicius' makeup that has helped him be successful: he's just really smart.

TinCaps manager Anthony Contreras has called the 6-foot-5 pitcher “a thinker” and Geaney said that the San Diego organization has gotten a similar impression.

“I think the coolest thing for us (San Diego executives) is how intelligent and what a good thinker he is,” Geaney said. “That's very much in a positive way. He's done his job, watching a ton of video.”

Margevicius has been the unquestioned ace of the TinCaps' staff ever since he took a no-hitter into the sixth on opening night. He bounced back from a couple of tough starts in a row to pitch seven innings of two-run ball against the first-place Bowling Green Hot Rods in his final start before the All-Star Break.

dsinn@jg.net