FORT MYERS, Fla. — Taking advantage of a deflated free agent market that’s seduced some of MLB’s greatest stars into long-term contract extensions this spring, the Red Sox followed suit on Friday, reportedly agreeing to a five-year contract extension with ace Chris Sale.

The agreement, which The Athletic reports is pending a physical and worth $145 million over five years, should guarantee the Red Sox are competitive through a window in which they were scheduled to lose some of their best players to free agency.

The Red Sox would not comment on the pending agreement, though sources indicated to the Boston Herald that a deal was near. The Boston Globe first reported that a deal was close.

“I haven’t checked my social media,” Manager Alex Cora said Friday afternoon. “Somebody mentioned Twitter was going off. I hear that. I can’t comment on it.”

That Cora named Sale the Opening Day starter says enough about what he thinks of the tall lefty.

“Everybody knows how good he is, what he brings to the table, not only on the field but off the field,” Cora said. “He’s one of the best.”

This season had a chance to be the last that the Red Sox were a juggernaut in the American League. Sale was set to be a free agent after the season, as are shortstop Xander Bogaerts, starter Rick Porcello, first basemen Steve Pearce and Mitch Moreland and utility man Brock Holt. J.D. Martinez can also opt out after 2019, though that seems more unlikely after National League MVP candidate Paul Goldschmidt’s long-term contract with the Cardinals paid him similarly to Martinez.

But by locking in Sale to an extension, the Sox will continue to have one of the strongest rotations in baseball, fronted by Sale (under team control through 2024), David Price (through 2022), Nathan Eovaldi (2022) and Eduardo Rodriguez (2021). For Sale, the extension represents another case of a star player likely taking a discount to stay with his current team, a pattern that’s become frequent this spring, as All-Star free agents like Dallas Keuchel and Craig Kimbrel remain unsigned less than a week before Opening Day.

At an annual average value of about $29 million per season, Sale will be making less than only four pitchers: Nationals’ ace Max Scherzer (about $30 million), Dodgers’ ace Clayton Kershaw (about $31 million), Price ($31 million) and Diamondbacks’ ace Zack Greinke (about $34 million).

Sale has been among the best in the game over the last five years, with a 2.85 ERA and a 0.99 WHIP in that time. To compare, Price had a 3.02 ERA and 1.10 WHIP in his five years before signing for seven years, $217 million. Greinke had a 2.82 ERA and 1.10 WHIP before signing for $206.5 million over six years with Arizona.

Could the 29-year-old Sale have gotten more money on an open market at the end of the season? Almost assuredly, as long as he stays healthy and productive. By signing now, he eliminates that risk to secure himself a guaranteed payday.

Shoulder issues limited him in 2018 but the Red Sox came into spring training this year optimistic that those issues were not a concern.

“He’s healthy,” principal owner John Henry said early this spring. “He had minor issues. They were able to take their time and give him some rest at one point, but he hasn’t had any significant shoulder issues – significant.”

Henry also said at the time that the Red Sox had learned from their mistakes with Jon Lester, to whom they offered a team-friendly contract a year before his free agent season only to have that come back to bite them when Lester halted contract negotiations and eventually departed to the Cubs through free agency.

“I think Chris falls out of the norm because he’s just such a great, not just a great pitcher but a great part of the team as we saw in the World Series,” Henry said in February. “He had quite an impact just being on the bench in the World Series. So he’s a special player. We would love to be able to sign him. I think he would like to as well. But there are the realities of the market place and budgets and this is his opportunity to be a free agent, potentially, which we’d like to avoid, but I think he would as well. So something could happen.”

On a Hall of Fame track, Sale has finished in the top-six in Cy Young Award voting for seven straight seasons and holds baseball’s all-time record for strikeout-to-walk rate (5.9) and strikeout-per-inning rate (10.9).

In the last year of a team-friendly contract originally signed when he was with the White Sox, Sale is making $15 million this year and was supposed to be a free agent after the season. Instead, he’ll double his salary and stay with the Red Sox.

In two seasons in Boston, Sale is 29-12 with a 2.56 ERA and 545 strikeouts. He had a career 3.00 ERA in Chicago.

Related Stories