OAKLAND, Calif. — At first glance, AJ Reed’s 6-4, 270-pound frame begs for membership in the White Sox’ big and tall club, a group including Adam “The Big Donkey” Dunn, Felipe “Jumbo” Paulino, Frank “Big Hurt” Thomas and 6-11 Jon Rauch. How Reed fits on the Sox’ 25-man roster is yet to be determined.

Once considered a highly regarded slugging prospect who was drafted by the Astros in the second round of the 2014 draft, Reed hasn’t been able to break through at the major-league level, hitting .153 with three home runs in 48 games. At Class AAA Fresno this season, Reed was batting .224/.329/.469 with 12 homers in 225 plate appearances and striking out 30 percent of the time.

The Sox are known for taking fliers on players with high pedigree who have struggled to make it in the big leagues. Reed, 26, who was waived by the Astros last week, was inserted into the starting lineup Friday in the Sox’ 5-1 loss to the Athletics, which kicked off a 10-game road trip.

Batting seventh as the designated hitter, Reed went 1-for-4.

“He’s someone the organization has targeted quite a bit from what I understand,” manager Rick Renteria said. “The hope is he can get on base, drive the ball out of the ballpark and play some [backup] first base [behind All-Star Jose Abreu].’’

After the Sox (42-45) cut Yonder Alonso, sent Daniel Palka back to Class AAA Charlotte and declined to give first-round catcher Zack Collins (1-for-22) more at-bats — all left-handed hitters — they had an opening for Reed.

Reed said he didn’t expect to be called up right away, hoping for a September promotion. So he’s thrilled.

“It’s going to be good for me just to get a fresh start somewhere, see some new faces, have some more eyes on me,” Reed said. “This is a good fit for me as a player.”

The Oakland Coliseum, meanwhile, continued to be a bad fit for the Sox, who are 1-6 there and 3-11 against the A’s (51-41) overall.

Ivan Nova (4-8, 5.60 ERA) gave up 10 hits in six innings, three of them solo homers, including back-to-back jacks to Ramon Laureano and Jurickson Profar in the third.

Fiers (9-3, 3.63) was much better, pitching 7 2/3 scoreless innings. Yoan Moncada, who had three of the eight hits against Fiers, raised his average to .314 and .396 since May 30 — the best average in baseball during that stretch.

The Sox have little to lose in giving Reed, once thought of as a future star in the Astros’ organization, a shot.

“They said they had been interested in me for a while, which helps my mentality and everything coming in knowing this is an organization that wants me out here to play and thinks I can succeed,” Reed said.

“It was just a logjam over there [in the Astros’ organization], especially for a guy like me who’s the low man on the totem pole, getting passed by several guys. I just had to get somewhere new, somewhere with more opportunity for me personally.”

Reed’s aforementioned size might have worked against him with the Astros in the end.

“When I was up in ’16, I had the slow start, and I think that kind of put a bad taste in their mouth,” he said. “They started working toward versatility defensively, and I’m a rather large guy, so I play first base. I feel like they felt like they needed guys who played more than one position, and I wasn’t able to do that for them.

“I’m just really excited to be here, really excited for the opportunity.”