4. Adrian Beltre, 1/8/2010
In January 2010, Beltre signed a one-year, $9 million contract with the Red Sox. At the time, he was coming off of some average years by his lofty standards and was looking to rehabilitate his value. Given this, he signed a one-year prove-it contract with the Red Sox and that is exactly what he did.
During his single season with the Red Sox, he hit for a .919 OPS with 28 home runs and 102 RBIs. He was an All-Star and won a Silver Slugger Award. As expected, he was able to parlay this great season into a multiyear deal with the Texas Rangers. He would go on to put up terrific numbers over the next eight seasons with the Rangers cementing himself as a future Hall of Famer.
His brief pitstop with the Red Sox has many fans wondering what if the Red Sox had re-signed him. For many Red Sox fans, he will always be the one that got away. Going forward, Beltre is a lesson that free agency comes with uncertainty and it is possible to hit the jackpot with some players who may not be at their peak value.
3. Mike Napoli 1/17/2013
Mike Napoli initially signed a three-year, $39 million deal with Red Sox but the deal fell through due to medical concerns. Fortunately for the Red Sox, he would eventually sign a smaller one-year incentive-laden contract with the team in January 2013.
He delivered beyond expectations on this contract. Napoli had a .842 OPS with 23 home runs and 92 RBI helping the Red Sox win 97 games on their way to a World Series Championship. In addition to his on-the-field contributions, Napoli and his facial hair was a key member of the Band of Bearded Brothers. Some lucky fans were able to celebrate with him after the World Series win demonstrating the mutual admiration between the city and the player.