BOSTON — Not every extension given to homegrown players is guaranteed to work out well for the team.

While pitcher Brayan Bello (six years, $55 million) and outfielder Ceddanne Rafaela (eight years, $50 million) continue to develop and show signs of being stars for the Red Sox, the deal handed out just four months ago to Kristian Campbell has yet to show signs of being a good investment.

Campbell, who made the team as the starting second baseman out of spring training without so much as a major league at-bat under his belt, was given an eight-year, $60 million extension. Following a strong start for which he was named the AL Rookie of the Month for March/April, Campbell struggled mightily before being optioned to Triple A Worcester in June.

But as the Red Sox announced a new eight-year, $130 million commitment to Roman Anthony Wednesday, there was little evidence that they were given pause by Campbell’s poor performance after his extension.

“We try to learn from every decision that we make,” said chief baseball officer Craig Breslow, “and that includes Kristian’s. But we still are incredibly confident of the contributions that Kristian is going to make to this organization over the next nine or 10 years.”

Initially, Campbell didn’t hit much better at Worcester than he did in the big leagues in May and June. But lately, as he’s grown more comfortable with the challenges of learning to play first base, his numbers at the plate have ticked up.

Entering Wednesday, Campbell was slashing .279/.405/.434 with four homers and 16 RBI.

“We’re starting to see him getting back into the form that we recognize and have come to appreciate over the last two or three weeks or so in Worcester,” said Breslow. “We’re still very, very confident about what he’s going to bring this team. And the way that we make decisions is pretty consistent.

“We look at information that we have, and that includes certainly performance and projections and those things; but we also look at people who know these players best because at the end of the day, we’re making bets on people. Roman, Kristian, Brayan, Ceddanne and Garrett — those are people that we’re willing to bet on.”

If you purchase a product or register for an account through a link on our site, we may receive compensation. By using this site, you consent to our User Agreement and agree that your clicks, interactions, and personal information may be collected, recorded, and/or stored by us and social media and other third-party partners in accordance with our Privacy Policy.