One year after their plan to go all-in backfired, the Padres and GM A.J. Preller are trying to pick up the pieces and move the team forward this season. They beat the Marlins on Sunday (SD 3, MIA 1) but are still 55-75 and sitting next to the Diamondbacks in the NL West cellar.

One bright spot for the rebuilding Padres has been rookie right-hander Luis Perdomo, a Rule 5 Draft pick from the Cardinals who had never pitched above Single-A prior to this season. He started the season as San Diego's mop-up reliever, then moved into the rotation once the Padres started trading away starters (James Shields, Andrew Cashner, etc.) at midseason.

The 23-year-old Perdomo had his best major league start on Sunday, holding the Marlins to one run on six hits in a complete game win. The sinkerballing Perdomo set a franchise record by recording six double plays. You can see all six right here. Dennis Lin of the San Diego Union-Tribune has some more details:

In recording the first complete game of his career, and the Padres' first this season, Perdomo worked in perfect concert with his defense. The 23-year-old rookie induced six double plays, etching his name as part of a new club record. The Padres' previous mark for double plays turned in a nine-inning game was five, last done in 2014. The major league record is seven, set by the Yankees in 1942 and matched by the Astros in 1969.

"Wow, that's awesome," third baseman Adam Rosales said when apprised of the new milestone. "It definitely speeds up the pace of the game, for sure, and it gives us the momentum. A guy gets walked or gets a base hit, and then it's, like, all right, you know you've got to kind of bear down, make sure you don't make it a long inning. Then, the next pitch, he gets a ground ball right at us. That's what (Perdomo's) sinker does, just turns into double plays. That's fun to play with."

Sunday's complete game win lowered Perdomo's season ERA to 5.84 (70 ERA+) in 115 2/3 innings, which obviously isn't very good, but that is largely due to some early season poundings he took in relief. Back in April he was just a kid from Single-A trying to cut his teeth in the show, and as he's gained experience, his performance has improved. Check out Perdomo's month-by-month splits:

April: 10.97 ERA and 2.63 WHIP
May: 9.39 ERA and 2.35 WHIP
June: 7.00 ERA and 1.67 WHIP
July: 3.99 ERA and 1.36 WHIP
August: 3.24 ERA and 1.44 WHIP

Those numbers sure seem to indicate the young man is getting more and more comfortable as a big leaguer as the season has progressed. The old saying is the biggest jump in baseball is from Triple-A to MLB, and the second biggest is Single-A to Double-A. Imagine making the jump from Single-A to MLB like Perdomo.

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So far this season Perdomo has a 59.5 percent ground ball rate, which is well above the 44.9 percent league average. Among the 119 pitchers to throw at least 100 innings in 2016, only Marcus Stroman of the Blue Jays has a higher ground ball rate than Perdomo. Stroman is at 60.9 percent. Jaime Garcia of the Cardinals is third at 57.2 percent.

The Padres may have found themselves a quality young starter in Luis Perdomo. USATSI

Interestingly enough, Perdomo did not start the season as a sinkerball pitcher. He threw a regular old four-seam fastball along with a curveball and a splitter-changeup hybrid. Perdomo has since replaced the four-seamer with a sinker. Check it out (via Brooks Baseball):

Prior to the Rule 5 Draft last December, Baseball America ranked Perdomo as the No. 24 prospect in the Cardinals' system in their 2016 Prospect Handbook, and their scouting report makes no mention of a sinker. "Perdomo's fastball has hit 97 mph ... He sits 93-94 mph and gets more groundouts than flyouts," said their write-up.

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Padres manager Andy Green told Lin that Perdomo is "extremely coachable," and it's possible the sinker is a relatively new pitch. Maybe not a new pitch entirely, but the modification of his normal fastball. It doesn't take much to turn a four-seamer into a sinker. Just offset the grip a bit and change finger pressure. The reason more pitchers don't use sinkers is control. It can be hard to locate the pitch consistently with all the extra movement.

Perdomo has allowed four earned runs total in his last three starts and 21 2/3 innings as he continues to settle into a groove and emerge as a legitimate rotation option for the Padres. Is he going to be an ace? Almost certainly not. But San Diego is in position to be patient with talented arms, and Perdomo is already rewarding that patience despite making the jump from A-ball to MLB.