The Boston Red Sox are expected to make another push to sign Jon Lester into a long-term deal in the coming days, but there is already a growing speculation that the veteran pitcher will become a free agent after this season.

Lester, who is 9-7 with 2.92 ERA in 17 starts for the Red Sox this season, turned down a four-year, $70 million offer in April. Recent reports suggested that Boston increased their offer, but Lester confirmed that there are no ongoing negotiations between the two parties.

"There has been no offer, there have been no new talks," Lester said via ESPN. "I've been talking to [general manager] Ben [Cherington] all along, but that's nothing new. There is no new offer. I don't think they've started anything. I know there's been conversation throughout the season, just different topics. Nothing about contract, numbers, anything like that."

With the Red Sox failing to secure a long-term deal last weekend, MLB analyst Buster Olney of ESPN believes that Lester will indeed head to free agency after the season and become one of the top free agents on the market.

"Jon Lester was tremendous down the stretch last year, he's now having one of the best seasons, if not the best season, of his career, and if he goes into free agency he is going to be one of the most prominent free agents, along with Max Scherzer," Olney said in an ESPN Radio interview.

Olney also added that the Red Sox blew their chances of keeping Lester when they decided to tender a $70-million offer, which was way below Lester's market value at that point.

Sources within the Red Sox organization reportedly told Olney that Lester, who has spent his entire nine-year career in Boston, would have agreed to a new deal had the club offered a five-year deal worth around $100 million.

"I think the Red Sox blew this," Olney added. "I think the contract talks are basically all but over before Lester becomes a free agent in the fall."