ARLINGTON, Texas -- If ever there was a time over the past six years when Steven Wright wondered whether he could pitch in the big leagues without his adopted knuckleball, he got a resounding answer Saturday night.

No chance.

Perhaps it was the moisture in the air on a typically oppressive summer night deep in the heart of Texas. Or maybe Wright simply didn't have it, and lord knows the Boston Red Sox right-hander was due for one of those starts in a first half of a season that has been straight out of a dream.

Regardless, Wright lacked all feel for the knuckleball and was forced to throw more fastballs than usual against the mighty Texas Rangers, who teed off for five innings. Wright gave up a career-high eight runs in a 10-3 loss that hiked his league-leading ERA from 2.02 to 2.18 and evened the best-of-three series between postseason hopefuls.

"I couldn't throw a knuckleball to save my life today," Wright said. "I felt like I couldn't throw a good one over the plate, so I had to rely a lot on my fastball. When I do that, it's usually not going to be a good day for me."

Indeed, there was a reason Wright began throwing the knuckleball. After he was drafted by the Cleveland Indians as a conventional pitcher, his career stalled in Triple-A in 2010. The Indians suggested he reinvent himself by becoming a knuckleballer, a tedious transition that took him back to Class A in 2011 but finally began to pay dividends last season, when he posted a 2.59 ERA in his final four starts for the Red Sox.

He had allowed more than three runs only once in a span of 18 starts entering Saturday, which left him in line to not only make the All-Star team but perhaps even start the game for the American League.

Even with as far as the floater has taken him, Wright still likes to mix in his fastball. Former Indians knuckleballer Tom Candiotti was the first to advise him to throw his knuckler when he's ahead or even in counts and the fastball when he's behind. But there have been times when Wright has surprised hitters with a heater. On Memorial Day, for example, he memorably struck out Baltimore Orioles slugger Adam Jones on an 85 mph four-seamer.

He had to lean on the fastball far too often in several different counts against the Rangers, though. He threw it 23 times out of 98 pitches, a 23.5 percent frequency. By comparison, he has thrown his fastball 16.2 percent of the time on average this season, according to ESPN Stats & Information.

"The catch-22 of using his fastball a little bit more is he generates a little bit more momentum going toward the plate," Red Sox manager John Farrell said. "Then he's got to consciously keep that posture over the rubber to execute his knuckleball, and that was a challenge for him here tonight."

It was no coincidence that Wright tied his season high by allowing three hits on fastballs: Mitch Moreland's two-run single in the fourth inning, Adrian Beltre's RBI single on a first-pitch heater in the fifth inning and Elvis Andrus' three-run triple on a full-count pitch that gave the Rangers a 7-2 lead.

"It's one of those days where, if you go against a team like this, as good as they are, and you don't have your good stuff, it makes for a long day," Wright said. "They were probably looking for [the fastball] the whole time because I wasn't able to show I could throw the knuckleball for strikes. Good teams like that, they'll be patient. Even when I did throw my fastball in a good count, it was up. When it's up, it defeats the whole purpose."

After his long stretch of quality starts, Wright can easily write one bad outing off as an anomaly. But that doesn't mean he wasn't trying to find answers for why his knuckleball went missing.

"That's what I was getting flustered by because I felt fine," Wright said. "The ball was spinning out of my hand. You'd think it was a little harder to grip the ball because of the humidity, but it was the opposite. It wasn't slippery. It was real sticky. It was the first time I've had that -- ever. I feel like I should have been able to figure it out, but it was one of those things where I started trying too hard.

"I tried changing speeds. I tried throwing curveballs. I was trying to throw the kitchen sink at them. It wasn't working."

By now, Wright knows what works for him. As long as his knuckleball returns Friday at Fenway Park, it will make what happened in Texas easy to forget.