In 2011, Kennedy narrowly lost out on the NL Cy Young Award to Clayton Kershaw. That year, Kennedy helped to lead the D-backs to the division title. Arizona would eventually lose in the first round of the playoffs. Since then, Kennedy hasn't been the same pitcher.
This season, even though Kennedy has improved since the All-Star break, he had been an extreme disappointment for the D-backs. He already has allowed 18 home runs.
Kennedy was averaging about six innings a start, putting more stress on an already overtaxed bullpen that has suffered many injuries. His control has been poor, hitting 10 batters this season. In a June game against the Dodgers, Kennedy's lack of control ignited a nasty incident, resulting in suspensions on both sides, including a 10-game suspension for Kennedy.
Every pitcher improves when he can hurl half of his games in Petco Park, despite the Padres bringing the fences in this year to generate more offensive production. The Padres hope Kennedy's performance improves with their tutelage and a less hitter-friendly home stadium. After this season, he is eligible for salary arbitration.
The D-backs needed to strengthen the bullpen to have any hope of making the playoffs. After they lost their superb left-handed reliever Matt Reynolds with a partially torn ulnar collateral ligament, the Diamondbacks needed to replace him. Although the team thinks Reynolds can begin a throwing program soon, his type of injury usually requires surgery.
For a long time, Thatcher has victimized the left-handed hitters in the NL West. They don't like facing him, but the righties don't enjoy it either. When the Diamondbacks lost Reynolds for a significant amount of time, everyone who follows the NL West knew the team would have problems staying competitive.
This trade reunites Thatcher with Heath Bell, who has struggled since he left the Padres after the 2011 season. During their time in San Diego, Bell was Thatcher's mentor. Since then, Thatcher sometimes closed for the Padres. Maybe reuniting Thatcher and Bell might help Bell rediscover the magic he had when they shared a bullpen.
Even though the Diamondbacks have the fifth-best bullpen in the NL, it needed help to remain strong throughout the season and beyond. The D-backs have had the second-most blown saves in the league, and these blown late-inning leads damage the team's morale. When entering the dog days of the baseball season, where everyone is tired and wants a break, a few blown saves can mean the difference for a playoff-caliber team making the postseason or not.
This can linger throughout the offseason and carry over to the next season, affecting how the manager runs his team and how the players perform. If obtaining Thatcher can decrease the number of blown saves, this trade for Arizona will be a huge benefit.
Unlike most teams, the Diamondbacks have depth in their starting rotation. Brandon McCarthy is returning to the starting rotation this week after being on the disabled list with shoulder inflammation. Since Kennedy hasn't won a game in two months, it made him expendable. It will be interesting to see if acquiring Thatcher will enable the D-backs to catch the red-hot Dodgers.