Jon Lester turned down extension offer worth $70 million

The Red Sox' latest extension offer to impending free agent Jon Lester was reportedly worth between $70 and $80 million over four years, writes Fox Sports' Ken Rosenthal.

Lester reportedly tabled extension talks late last month, but he left open the possibility for the two sides to negotiate in season. However, the left-hander appears to have changed his mind, as sources tell Rosenthal that Lester will not reopen negotiations until after the season.

Lester has expressed a desire in recent weeks to stay with the Red Sox, and despite the rather low extension offer, he still wouldn't rule out the possibility of remaining in Boston, telling ESPN Boston's Gordon Edes "why does it mean I'm out of Boston?" and saying that "things can definitely change."

Lester on @Ken_Rosenthal report on status of contract talks: "Why does it mean I'm out of Boston...things can definbitely change.''.

— Gordon Edes (@GordonEdes) April 12, 2014

The size of Lester's reported extension offer is somewhat peculiar considering the massive contracts handed out in recent years to the likes of Homer Bailey, Adam Wainwright, Matt Cain, and Cole Hamels. It is also significantly less than the deal that Tigers' right-hander Max Sherzer turned down earlier this year.

The 30-year-old Lester owns a career 118 ERA+ and 28.5 WAR. He has been an instrumental part of Boston's success in recent years, helping them to two championships in 2007 and 2013. Lester currently has a 2.57 ERA with 20 strikeouts in 21 innings through his first three starts. Last year, he went 15-8 with a 3.59 FIP, 8.57 K/9, and 4.3 WAR.