PITCHER JON LESTER agreed to a $155 million, 6-year contract with the Cubs, the first big deal of the offseason involving a top-level starting pitcher and one Chicago hopes will help end more than a century of frustration at Wrigley Field's Friendly Confines.

Lester's contract, agreed to on Tuesday night, contains an option for 2021 that, if it becomes guaranteed, would make the deal worth $170 million over seven seasons. The average annual value of $25.8 million is the second-highest for a pitcher behind Clayton Kershaw's $30.7 million as part of a $215 million, 7-year deal with the Los Angeles Dodgers that began this year.

A three-time All-Star who turns 31 next month, Lester won two World Series titles over eight-plus seasons with Boston. The lefthander joins a long-suffering team with a promising core of young players and a top-tier manager Joe Maddon, who left Tampa Bay and signed a $25 million, 5-year contract with the Cubs last month.

Yesterday, Lester took to Twitter to express his feelings about the deal.

"Extremely difficult decision for me and my family but we love the outcome and couldn't be more excited to join the Cubs organization!" he wrote. "To Red Sox Nation, I understand the disappointment. Boston will always have a big place in my heart and we'll always consider y'all family!"

Lester was dealt by the Red Sox to Oakland at the trade deadline in July and helped the A's reach the playoffs for the third straight year before a 9-8, 12-inning loss to Kansas City in the AL wild-card game. He went 16-11 with a career-best 2.46 ERA and 220 strikeouts last season and is 116-67 with a 3.58 ERA in nine big league seasons.

Lester is headed to a team that hasn't made the playoffs since 2008 and hasn't won the World Series since 1908.

"It's not often you get to win the lottery, and we won the baseball lottery this year," Maddon said of acquiring Lester. "Now it's up to us to put it into effect."

Noteworthy * 

Closer David Robertson and the Chicago White Sox have finalized a $46 million, 4-year contract.

The righthander, who turns 30 in April, gets $10 million next year, $11 million in 2016, $12 million in 2017 and $13 million in 2018 under the agreement announced Wednesday.

He was 4-5 with a 3.08 ERA and 39 saves this year, when he took over as the New York Yankees' closer following Mariano Rivera's retirement.

As part of the contract, Robertson, who spent seven seasons with the Yankees, cannot be traded without his consent to the Philllies, Mets, Detroit, the Los Angeles Dodgers, or Oakland.

* The Houston Astros have bolstered their bullpen by agreeing to an $18.5 million, 3-year contract with Luke Gregerson and a $12.5 million, 2-year deal with Pat Neshek, people familiar with the negotiations said.

Gregerson, 30, spent 5 years with San Diego, then went 5-5 with a 2.12 ERA in 72 appearances for Oakland last season. Neshek, 34, has pitched for Minnesota, San Diego, Oakland and St. Louis. He was 7-2 with a 1.87 ERA for the Cardinals last season.

* Bryce Harper's agent is having talks with the Washington Nationals ahead of a possible grievance hearing to decide whether the outfielder should be eligible for salary arbitration.

Harper has 2 years, 159 days of major league service, 26 above the cutoff for arbitration eligibility this offseason. Agent Scott Boras contends because the All-Star has sufficient service time, he should be able to void the 2015 terms in the final season of his $9.9 million, 5-year contract.

Boras says "I'm in discussions with the Nationals on that subject."

* Alex Rodriguez remains over the weight the New York Yankees want him to be at when he reports to spring training in 2 months.

Yankees general manager Brian Cashman said Matthew Krause, the team's strength and conditioning coordinator, visited A-Rod in Miami.

"Like all our players, you have a report weight we're hopeful that they hit," Cashman said. "He's approaching that. He's not at that spring-training weight that we desire just yet.

Rodriguez is coming off a season-long suspension for violations of baseball's drug agreement and labor contract. The third baseman turns 40 in July.

* Dick Enberg has won the Ford C. Frick Award for excellence in baseball broadcasting.

Baseball's Hall of Fame made the announcement at the winter meetings.

Enberg has been calling Major League Baseball games in Southern California for nearly 20 seasons, split by stints as one of the most recognizable voices on NBC and CBS.

Enberg, who will be 80 next month, is the 39th winner of the Frick Award. He will be honored during the Hall of Fame awards presentation on July 25 in Cooperstown, New York.