The bidding for top free agent starting pitcher Yoshinobu Yamamoto is heating up, and the Red Sox are reportedly still in the mix.

According to The Athletic’s Jim Bowden, the Red Sox and San Francisco Giants are making a strong push for the Japanese right-hander and have each made an offer in excess of $300 million.

Bowden posted his initial report on X (formerly Twitter) and expanded upon it during an appearance on MLB Network Radio on SiriusXM Sunday morning.

“I heard yesterday that the Giants and Red Sox, not only were making a strong late push and were legitimately in this thing, but that the number had gone over $300 (million),” Bowden said, adding that the exact figures aren’t known and that the $300 million may include the posting fee that would be paid to Yamamoto’s former Japanese club. “The one thing also I heard is teams are trying to give more years to get the (average annual value) down for the luxury tax, so don’t be surprised if his deal ends up being 12 or 13 years, or even 14 years, which we’ve never seen for a pitcher.”

Spanish-language Red Sox reporter Marino Pepén also reported the $300 million offer and added Sunday that the number could rise and the club expects to be in it until the end. Pepén also reported Yamamoto has accepted an invitation to visit Fenway Park.

Outside of Shohei Ohtani, Yamamoto has become the most highly coveted free agent on this year’s market and has drawn interest from virtually all of MLB’s financial heavyweights. According to the New York Post’s Joel Sherman Yamamoto also met with the New York Mets at owner Steve Cohen’s house over the weekend, and according to SNY’s Andy Martino will meet with the Yankees while in town as well.

Why is Yamamoto drawing such intense interest? The 25-year-old has posted a 1.82 ERA in seven seasons with Nippon Professional Baseball and has won both Eastern League MVP and the Sawamura Award (Japan’s equivalent to the Cy Young) in three consecutive seasons. Scouts project Yamamoto could slot in as an ace immediately upon his arrival in MLB, and it’s extremely uncommon for that level of talent to hit the open market at such a young age.

Yamamoto must sign with an MLB club by Jan. 4, the date his 45-day posting window expires.