Unfortunately for Roark, his last three starts have been a completely different story. The 32-year-old has allowed 14 earned runs in 14 1/3 innings for an ERA of 8.79.
Sunday's outing against the Rangers was Roark's worst of the season. He surrendered a career-high four home runs and gave up five earned runs in just three innings, as Texas breezed to an 8-3 win.
"(This loss) is on me," Roark said after the game. "It was a rough outing altogether. (They were) putting good swings on bad pitches. I left the ball over the plate a lot of times and when you do that in this league, they get hit hard and they get hit far."
A's manager Bob Melvin offered insight into what happened to Roark.
"They were just on him early," Melvin said. "A lot of times, when you have a chance (against) a good starter, it's early in the game. They got him before he could get into his rhythm and hit some balls out of the ballpark. ... It doesn't minimize our feeling about Tanner. He's been great for us."
While that may have been true last month, it's not quite the case anymore. In nine starts with the A's, Roark has a 4.50 ERA. At this point, he seems unlikely to be in the starting rotation if Oakland reaches the American League Division Series, especially considering how well the team's other starters have pitched.
Sean Manaea and Mike Fiers have been excellent, while Homer Bailey has looked phenomenal in his last seven starts. That likely leaves Roark, Brett Anderson, and Chris Bassitt battling for the No. 4 job.
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Even if the A's elect to keep Bassitt in the bullpen, Anderson has been far more consistent than Roark, allowing three earned runs or fewer in six straight starts.
The A's still have six games remaining in the regular season, which means Roark might get one more chance to make a better statement. But as of now, he has to be the odd man out.
Tanner Roark pitching his way out of A's potential MLB playoff rotation originally appeared on NBC Sports Bay Area