BOSTON — Corey Kluber worked six scoreless innings and the Tampa Bay Rays beat the Red Sox 7-1 on Wednesday night in the major league debut of Brayan Bello, the top pitching prospect in Boston’s system.

With a fastball topping out at 97 mph, the 23-year-old Bello (0-1) worked four up-and-down innings, allowing four runs on six hits with three walks and four strikeouts. The right-hander finished his 79-pitch outing by retiring two batters after Josh Lowe’s one-out double.

Randy Arozarena had a two-out, two-run double in the third against Bello, and Kevin Kiermaier had another run-scoring double to make it 4-0. Arozarena added a solo homer in the ninth off Tyler Danish.

Kluber (4-5) allowed three hits with no walks and five strikeouts.

Yandy Diaz doubled with one out in the first for the Rays and scored on Wander Franco’s single.

Tampa Bay extended its lead to 6-1 in the sixth against Hirokazu Sawamura on Lowe’s run-scoring double and a bases-loaded walk by Ji-Man Choi.

J.D. Martinez had an RBI single for Boston in the eighth.

TRAINER’S ROOM

Rays: INF/OF Brandon Lowe, out since May 16 with low back discomfort, is expected to begin a rehab assignment by playing designated hitter for Triple-A Durham on Thursday.

Red Sox: LHP Chris Sale, out all season with a stress fracture in his right rib cage, made what could be his last rehab start, allowing one run on three hits and five walks with five strikeouts in 3 2/3 innings for Triple-A Worcester. ... 3B Rafael Devers was out of the lineup with a sore back and a sore right hamstring. ... CF Kiké Hernández, out since June 8 with a right hip flexor strain, is expected to start a rehab assignment on Friday. ... LHP Josh Taylor, out all season with a low back strain, also made a rehab appearance for Worcester, striking out three in one inning. ... LHP Rich Hill, sidelined with a left knee sprain, threw from flat ground. ... RHPs Nathan Eovaldi, out since June 9 with low back inflammation, and Garrett Whitlock, out since June 9 with right hip inflammation, could start rehab assignments soon, manager Alex Cora said.

INCOMING

INF Yu Chang, claimed off waivers from the Pittsburgh Pirates on Tuesday, is expected to join the Rays for the start of their three-game series at Cincinnati on Friday.

UP NEXT

Rays: Left-hander Shane McClanahan (9-3, 1.74) is set to make his first career appearance against the Reds on Friday, opposed by right-hander Luis Castillo (3-4, 3.09).

Red Sox: Start a four-game series against the rival New York Yankees on Thursday with rookie Josh Winckowski (3-2, 3.12 ERA) facing Gerrit Cole (7-2, 2.99). Winckowski will pitch against the Yankees for the first time.

Howard Herman can be reached at hherman@berkshireeagle.com or 413-496-6253.