But Seattle center fielder Dustin Ackley made a sliding catch on the warning track, catching the ball just as it descended to the dirt surface.
Middlebrooks, who earlier in the game snapped a 0-for-22 hitless streak with a hard single, watched the replay on the mammoth video board at Safeco Field. What he didn't do was kick himself over what was a missed opportunity.
"I'm not a 'why me' guy," Middlebrooks said Wednesday. "My job is to hit the ball hard, I did that. His [Ackley] job is to go get it, which he did."
Middlebrooks, who got the start at third base in the series finale, is hitting .194 this season. His single Tuesday was his first hit since April 27 against the Astros.
Dig deeper inside the numbers and Middlebrooks' funk might be more about bad luck than bad approach or mechanics. His BABIP (batting average on balls in play) is just .213, which suggests he's been unlucky more than awful at the plate and that he could be in for better luck ahead.
Middlebrooks had a .335 BABIP in 2012 with the Red Sox and marks of .263 and .273 the last two years.
"He's had some at-bats where he's hit the ball hard and has had nothing to show for it," said San Diego manager Bud Black. "All you can do as a player is hit the ball hard. The hitter can control the hard contact, but for the most part, the hitter can't control the ball.
"We just need him to have good at-bats, hit the ball hard and, hopefully, the hits show up."
Middlebrooks hasn't done any real tinkering with his approach or swing mechanics during this rough stretch. He's seeing the ball fine. The results just haven't been there. But he's trusting the process.
"I'm just not getting hits. That's a little tough to swallow. But it's part of the game. It's tough. At the same time, I've got to keep my head straight," he said. "Hopefully it turns around."
Could Middlebrooks' luck be turning?
He squared up a pitch from Mariners pitcher Taijuan Walker in the third inning Wednesday, hitting it over the left field wall. The Padres went on to defeat the Mariners, 4-2.