BOSTON -- The Boston Red Sox traded right-hander John Lackey to the St. Louis Cardinals for right-hander Joe Kelly and outfielder Allen Craig before Thursday's deadline.
The deal leaves the Red Sox without their top two starters. Both teams announced the move a few hours after the struggling Red Sox said they had sent their No. 1 starter, left-hander Jon Lester, to the Oakland Athletics with outfielder Jonny Gomes and cash for slugging outfielder Yoenis Cespedes and a 2015 draft pick.
[NEWS: A's land Lester, ship Cespedes]
The Red Sox also sent cash and minor league left-hander Cory Littrell to St. Louis.
Lackey is 11-7 with a 3.60 ERA in the fourth year of a five-year, $82.5 million deal.
Kelly is 2-2 with a 4.37 ERA in seven starts. He has made four starts since being activated from the disabled list on July 11. Craig is batting .237 with seven homers and 44 RBIs.
Lackey has had two strong seasons since being sidelined for all of 2012 after undergoing Tommy John surgery.
He was 10-13 with a 3.52 ERA last year when he pitched his second World Series-clinching game, allowing one run in 6 2-3 innings in a 6-1 win over the Cardinals in Game 6. In 2002, he won Game 7 for the Anaheim Angels over the San Francisco Giants, a 4-1 victory in which he gave up one run in five innings.
The Cardinals, in a tight race with the Milwaukee Brewers and Pittsburgh Pirates in the NL Central, had obtained right-hander Justin Masterson from the Cleveland Indians on Wednesday.
[RELATED: MLB standings]
Kelly joins a Red Sox rotation with a much different look than the one that began the season.
Lester, Lackey, Jake Peavy and Felix Doubront all are gone. Peavy was traded to the San Francisco Giants last Saturday and Doubront was sent to the Chicago Cubs on Wednesday. Only Clay Buchholz, an inconsistent right-hander, remains from the original group.
The 26-year-old Kelly was 5-7 with a 3.53 ERA as a rookie in 2012 and 10-5 with a 2.69 ERA last season.
Craig brings more power to a weak-hitting outfield that was bolstered by the acquisition of Cespedes. In the past two seasons, Craig totaled 35 homers and 189 RBIs, hitting .307 in 2012 and .315 in 2013.
The 30-year-old Craig has been in a season-long slump after batting a major league-best .454 with runners in scoring position in 2013. He's gotten days off to help emerge from his slide with little success. He hasn't been the same since missing the last month of regular season with a left mid-foot strain but came back for the World Series, playing some designated hitter and first base.
Kelly and Craig both were hurt running to first, Craig when he landed awkwardly rounding the base and Kelly injuring his hamstring sprinting to beat out a bunt.
While the Cardinals make their playoff push, the Red Sox are in last place in the AL East and looking ahead to next season. With the departure of four veteran starters, several of their top prospects should get a long look the rest of the season.