ARLINGTON -- The Rangers dug themselves into an early hole against the Red Sox on Friday night and were never able to get out of it. Starting pitcher Kohei Arihara started the game by yielding back-to-back walks, followed by back-to-back home runs, leaving Texas with an early deficit before ultimately falling to Boston, 6-1, at Globe Life Field.

“His stuff just doesn’t look the same,” said Rangers manager Chris Woodward. “The velocity is down. The split-finger is just not as sharp. Typically, when the velo is down, everything else suffers. We asked him and he said he feels fine. I don't know if it's something we're gonna have to address, because what he had tonight doesn't look anything like what we had seen in the past.”

It marked the second start in a row for Arihara where he wasn’t able to get through the third inning, following a six-hit, five-run outing in Chicago on Sunday. He said that the starts vs. the White Sox and Red Sox felt similar to him, emphasizing how he wasn’t able to pitch the way that he wanted to.

Woodward said that the staff isn’t sure about what’s causing Arihara’s decline, but the righty said that he believes once he fully gets used to the MLB schedule and working on four days’ rest -- instead of the typical five in Japan -- everything will come together for him.

Pitching coach Doug Mathis said last week that he wasn’t worried about Arihara’s early struggles and that he was doing a lot of good things on the mound. Mathis agreed that once Arihara makes adjustments to Major League hitters and controls the strike zone, he’ll get more swings and misses and strikeouts, instead of home runs allowed.

The conversations between Arihara and the staff will have to take place soon. Woodward said that Arihara’s velocity was way down from what it had been in the past, which could be due to the fatigue of a new schedule. They want to figure it out and correct it for him as soon as they can. Per Statcast, Arihara is in the bottom 10 percent of Major League pitchers in average exit velocity, max exit velocity and hard-hit rate.

“We'll figure it out and hopefully get him back on track,” Woodward said. “I don't have an exact answer for it, but we saw in Spring Training him get up to 94 mph at times. Not consistently, but it was consistently at 90-91. Today was pretty much consistently 86-87 mph. A couple of 88s, but he barely touched 90 at times. It just makes it tough because everything else suffers in his repertoire.”

Arihara gave up four home runs against the Red Sox. At the conclusion of their game, the Rangers’ pitching staff led the Majors in home runs allowed with 39. Arihara has given up six himself.

Woodward said that it’s something they’ve noticed and are actively working to address in the clubhouse.

“I think that comes with throwing strikes,” Woodward said. “I think at times, give credit to the hitters, they haven't missed too many advantage count fastballs.

“We're definitely addressing that as far as when we do throw the ball over the plate, especially in advantage counts, trying to execute pitches that limit slug. We don't want to lead the league in homers, but at the same time, we do want to pound the strike zone.”

Hyeon-Jong Yang relieved Arihara in the third and pitched 4 1/3 scoreless innings, allowing just one hit while notching four strikeouts. Though Yang was able to hold off Boston from tacking on runs, the Texas offense also came up largely empty, stranding nine runners on base.

The Texas bullpen has been phenomenal in recent contests, extending its consecutive scoreless-innings streak to 19 through four games at the conclusion of the Red Sox outing.

• Need relief? Yang's the man

“[Yang] is not afraid,” Woodward said. “He kind of looks at it as, 'There's really not a hitter in there and I got to execute my pitch.' He's done that his whole career in Korea. For him to trust it against some of the best hitters in baseball just shows you how much conviction he has in stuff.”