The last time Rodriguez had a rough beginning to a game was on June 12 against the Twins, when he had an issue with a new foot insole that bent and caused him discomfort.
After removing the insole, Rodriguez went on to throw 6 2/3 innings, with the only earned run coming in the first.
But on Wednesday, Rodriguez allowed five runs in the first and three in the second in what became his worst outing of the season. It was the Rangers' fourth straight loss and ended a streak of six consecutive wins in Rodriguez's starts.
It also snapped a run of six straight starts in which Rodriguez allowed three earned runs or fewer.
"He didn't seem to be able to find the range with the breaking ball, and they were on his fastball," manager Jeff Banister said. "Tough night when you get down eight runs. We tried to get as much out of Wandy as we possibly could."
Rodriguez allowed doubles to two of the first three Oakland hitters. After walking Josh Phegley and Billy Butler, he gave up a grand slam to Brett Lawrie in the first. Rodriguez surrendered another home run to Phegley in the second.
Rodriguez was able to grind out four innings on 94 pitches, but he appeared to be in discomfort on the mound. The lefty said he felt like he didn't have his best stuff on his fastball, but he didn't have an explanation for it.
"I feel good," Rodriguez said. "But today I felt my ball [didn't have] speed. I tried to throw hard, but something, I don't know."
The damage was done, but right-hander Anthony Bass saved the Rangers' six-man bullpen with four innings of two-hit relief and five strikeouts. Banister called Bass' outing the story of the game.
"Terrific job by Anthony and really something that we needed tonight," Banister said. "Impressive, the number of zeros that are up on that board, he and Sam [Freeman] coming in and doing what they did for us tonight to keep some of those arms out of play."
Rodriguez's short night could still have lasting effects, though. Bass is likely to be unavailable for Thursday's series finale, and despite Ross Detwiler having the ability to serve as a long man, the short bullpen could be under added stress if the team does not make a roster move.
It was a bad night for Rodriguez any way you cut it, but the good news is he has been solid in almost all of his 12 outings this season, and the 36-year-old should have the veteran savvy to recover assuming his body can do the same.
"Tough one, but we'll move on from it," Banister said. "I'm sure Wandy will erase this from his memory bank. If I know him well, he'll figure out what went wrong and move on."
Cody Stavenhagen is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.