Yogi Berra once famously said, "Baseball is 90 percent mental. The other half is physical."

His numbers might have been a little off, but the sentiment is spot on. Jurickson Profar certainly can attest to that.

The A's second baseman committed his seventh error of the season Monday night, leading to six unearned Red Sox runs, sending the A's to their fourth straight loss, 9-4.

Profar's seven errors are three more than any other second baseman in Major League Baseball this season. Even more troubling, six of the seven have been throwing errors and they haven't even been close.

That was the case on Monday when Profar fielded a routine double-play ball in the third inning and spiked it into the dirt, about 10 feet shy of second base. A few plays later on another routine ground ball, he carefully lobbed the ball to first base, seemingly afraid to throw.

It appears Profar has come down with a nasty case of the yips. There have been several instances of the yips wreaking havoc in baseball over the years. Former Dodgers second baseman Steve Sax is probably the most famous case.

In 1983, Sax suddenly became unable to make routine throws to first base, committing a career-high 30 errors that season. Former Yankees second baseman Chuck Knoblauch developed a similar problem in 1999, finishing with 26 errors, most of them wildly inaccurate throws.

Current Cubs pitcher Jon Lester has battled his own case of the yips where he can't throw the ball to first base. Fortunately for him, it hasn't affected his pitching ability.

Profar hasn't played a ton of second base in his career and is still learning the position. Last season with the Rangers, he spent most of his time at third base and shortstop, playing just 10 games at second.

"Different position, different angles," A's manager Bob Melvin told reporters Monday. "We're working. At some point, he'll get comfortable there."

Profar has already sought advice from Oakland shortstop Marcus Semien, who dealt with his own defensive struggles early in his career.

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"I'm ready to keep working," Profar told reporters. "I talked to Marcus a little bit and he talked to me about it and what he did. I'm going to follow his steps and try to get better to help my team win."

At the moment, Profar seems to be overthinking every play at second base, a primary symptom of the yips. Whether he can overcome them remains to be seen. But right now, his errors are costing Oakland games.