SEATTLE — Andrew Benintendi didn’t take long to make adjustments major league hitters have to make.

After going 0 for 2 with a strikeout in his major league debut Tuesday night, when he entered the game in the seventh inning as a pinch hitter, he produced two singles (and a swinging strikeout) in his first major league start in left field in the Red Sox’ 3-1 loss to the Mariners on Wednesday night.

Those who have watched Benintendi cautioned to be patient with the 22-year-old, noting that he has tended to struggle at first in a new league before turning things around.

One never knows how a player will react. He could be like Jacoby Ellsbury and shine. He could be like Jackie Bradley Jr. and struggle. He could be like Xander Bogaerts and look impressive early then struggle in his first full year in the majors.

Benintendi’s poise and makeup suggest he’s worth the risk. One talent evaluator from a National League East team said, “If he struggles, he’s the type of kid who’s good enough to make the adjustments and get up to speed in a hurry. I see why the Red Sox did this. He would have excelled at Triple A had he been sent there, but for some reason they didn’t allow him to see the next level. It’s always been a debate as to how much a kid benefits by Triple A. The only thing you like to see is that progression to each level and see how he handles it.’’

Benintendi struggled when he first got to Double A, but he got out of it quickly and then started to show his ability, hitting close to .300 for most of his time there.

“That’s the thing,’’ said the evaluator. “It doesn’t take him long. He may struggle to get his bearings at first, but you can’t abandon him once you’ve made the decision that he’s going to be in there. They’ve got to let him fail a little. I know they’re in a tough race in their division, but they made the choice to call him up. Once you make that commitment you need to stick it out for a while.’’

And that would seem to be the Red Sox’ plan. They batted him ninth on Wednesday and he’ll play against righthanded pitching. But Benintendi’s production will dictate where he goes from there. To some degree, the Red Sox know they are rushing things. That’s why Benintendi is being handled with kid gloves. That’s why he was batting ninth and facing a righthander. Ease him in.

For all the care the Red Sox are showing, they know Benintendi must sink or swim on his own merits. At the end of the day he owns the 0 for 2 in his major league debut, but even manager John Farrell tried to give him the out, saying, “[Benintendi] took a long flight and a few hours later he was getting his first major league at-bat.’’

Benintendi spent Wednesday morning with his family but got to the ballpark early to continue his acclimation to the majors. He sat in on a card game in the clubhouse with Dustin Pedroia, Chris Young, and Bogaerts, and he seemed to be blending in well and winning the approval of his older teammates.

Benintendi is not only young, but he looks half his age. If he walked around without his uniform you’d think he was one of the clubhouse kids or the son of a player. He walked out to the field and looked around at Safeco Field. “I’d never been here before,’’ he said. “This is such a nice ballpark and a nice city.’’ He was experiencing things for the first time and there was a joyful innocence about it.

As the seventh overall pick in the draft, Benintendi is expected to be in the same echelon eventually as Bogaerts, Bradley, and Mookie Betts. We’re sure that by September Yoan Moncada will likely be with the big club as well, at least to be a pinch runner. Moncada already is taking grounders at third before games and also appearing in the outfield, but for now he’s still playing second base. It would appear that Moncada will be changing positions, likely moving to third, as soon as the Sox solve the riddle of how to position Travis Shaw, Hanley Ramirez, and Pablo Sandoval next season.

Shaw could become trade bait. Sandoval could retake the third base job, depending on his weight control. Ramirez could stay at first base or move to DH. Sandoval could move to DH. Shaw could go to first. What is known is that Moncada will be a starter someplace. And that could mean the Red Sox get both Benintendi and Moncada in their 2017 lineup, with the possibility that Blake Swihart stays behind the plate with Christian Vazquez.

So much to sort out.

Benintendi, however, is part of the future solution. Sure, he could be trade bait if the Red Sox desperately need to reinforce their starting rotation with a big name such as Chris Sale or Jose Fernandez, but otherwise he’s very much in the outfield plan. The Red Sox will have controllable, talented outfielders not seen in Red Sox Nation since Jim Rice, Fred Lynn, and Dwight Evans. Betts and Bradley are already All-Stars, and the word is Benintendi can be as well.

“From what I’ve seen of this kid, he defies the odds,’’ said the evaluator. “He’s got a quick bat, fast hands like Mookie. He’ll surprise you with his power and he’ll get bigger and thicker as he gets older, so the power will become more pronounced in time. For now, he’s a good hitter who can drive the ball to all fields. He’s a plus defender. He’s going to grow on you. His play may start out slow, but he’ll turn it up, so be patient. Don’t judge him on the first week or two. Let him settle in.’’

Sure thing.