Kristian Campbell, left, runs the bases past third-base coach Kyle Hudson after hitting his first major-league home run Saturday against the Texas Rangers. LM Otero/Associated Press

BALTIMORE — Kristian Campbell agreed to a $60 million, eight-year contract with the Boston Red Sox on Wednesday, less than a week after his major league debut.

He gets a $2 million signing bonus, half payable within 60 days of the contract’s approval by Major League Baseball and half next Jan. 15. He receives salaries of $1 million this year, $2 million in 2026, $3 million in 2027, $4 million in 2028, $6 million in 2029, $9 million in 2030, $13 million in 2031 and $16 million in 2032. The deal includes a $19 million team option for 2033 with a $4 million buyout and a $21 million team option for 2034 with no buyout.

Salaries for 2031-34 can escalate based on accomplishments in the immediately preceding season: $200,000 for making the All-Star team, $2 million for winning an MVP award, $1 million for finishing second or third in the MVP voting, $500,000 for fourth or fifth, and $250,000 for sixth through 10th.

A 22-year-old infielder and outfielder, Campbell made his big league debut March 27 as Boston’s youngest Opening Day starter at second base since Reggie Smith in 1967. He entered Wednesday hitting .375 (6 for 16) with two doubles, one homer, two RBI and four walks.

Campbell agreed to the deal with just six days of major league service time. Boston struck a big-money deal with a rookie for the second straight year, following a $50 million, eight-year contract last April with outfielder/infielder Ceddanne Rafaela, who started 2024 with 35 days of service time.

Campbell’s new deal supersedes a one-year contract paying the $760,000 minimum while in the major leagues.

PADRES: All-Star outfielder Jackson Merrill agreed to a $135 million, nine-year contract covering 2026-34.

Merrill had a sensational rookie season in 2024 and said several times he wanted to stay long term with the Padres.

“An opportunity to sign with the San Diego Padres is enough for me. But I also feel like there comes a line where you know your worth, you know your value,” Merrill said at a news conference before the Padres played Cleveland. “Listen, I know there are contracts out there that are beyond absurd, there’s super amounts of money. But having a relationship with a real human being and a real team like I have here, you can’t beat that.”

Merrill, who turns 22 on April 19, was moved from shortstop to center field in spring training last year when the Padres had only two outfielders on their roster. He made the Opening Day roster and hit .292 with 24 homers, 90 RBI and 16 stolen bases. He finished second in NL Rookie of the Year voting behind Pittsburgh pitcher Paul Skenes.

He’s had a least one hit in every game this season and has helped the Padres to the first 6-0 start in their 57-season history.

“The Padres were the first team that ever reached out to me, ever scouted me,” he said. “They believed in me from Day 1. They wanted me. It feels good to be wanted. I always felt they had a certain trust in me.”

Merrill gets a $10 million signing bonus, $1 million payable within 30 days of the contract’s approval by Major League Baseball and $3 million on Jan. 15 in each of the next three years.

He gets salaries of $1 million in 2026, $6 million in 2027, $8 million in 2028, $10 million in 2029 and $20 million annually from 2030-34.

San Diego has a $21 million option for 2034 that would become a player option at the same salary if he finishes among the top five in MVP voting in any season from 2026-34.

SALARIES: Major League Baseball’s average salary broke the $5 million barrier on Opening Day for the first time, according to a study by The Associated Press.

The New York Mets, with Juan Soto’s record $61.9 million salary, led MLB for the third straight Opening Day with a $322.6 million payroll, just ahead of the World Series champion Los Angeles Dodgers at $319.5 million. Those two teams each spent roughly five times as much as the Miami Marlins, who at $64.9 million ended the Athletics’ three-year streak as the lowest spender.

Still, the Mets were down from their record high of $355.4 million in 2023.

The average rose 3.6% to $5,160,245. That was up from a 1.5% increase last year but down from an 11.1% increase in 2023.

PIRATES: Pittsburgh outfielder Bryan Reynolds was limited to designated hitter duties for the third consecutive game Wednesday because of right arm discomfort.

Reynolds is dealing with what the team calls triceps soreness, a minor but lingering issue.