~ St. Louis traded for shortstop Julio Lugo

ARLINGTON, Texas -- The Boston Red Sox added some depth a day after they dropped out of first in the AL East, and got rid of shortstop Julio Lugo in one of Wednesday's deals.

Boston traded Lugo and cash to the St. Louis Cardinals for outfielder Chris Duncan, announcing the swap hours after they acquired first baseman Adam LaRoche from Pittsburgh for two minor leaguers.

Lugo, who signed a $36 million, four-year free-agent deal before the 2007 season, was designated for assignment Friday and is owed about $13 million through next season.

General manager Theo Epstein has called Lugo's contract "a mistake" and "a lesson learned."

Duncan, the son of Cardinals pitching coach Dave Duncan, hit .227 with five homers and 32 RBIs in 87 games for St. Louis. The Cardinals had optioned Duncan to Class AAA Memphis after Tuesday night's game in Houston. The Red Sox sent the 28-year-old outfielder to their top affiliate, Pawtucket.

Lugo, who provides St. Louis with middle infield depth, was batting .284 with one homer and eight RBIs in 37 games, with seven errors.

"We're optimistic that he will respond positively to a fresh start here in St. Louis," Cardinals general manager John Mozeliak said.

Boston made the deals a day after losing the division lead for the first time since June 9. The Red Sox dropped their fifth straight game Wednesday night at Texas.

The New York Yankees beat Baltimore 6-4 on Wednesday for their sixth consecutive win, moving two games ahead of the Red Sox.

LaRoche hit .247 with 12 homers and 40 RBIs in 87 games for the Pirates. He will join the Red Sox, who are off today, for the opener of their next series, Friday night against Baltimore at Fenway Park.

"There's some uncertainty with our health, some concern in the organization about enough depth where if something does happen, where do we go," Boston manager Terry Francona said. "He's a good left-handed hitter. He doesn't have to carry the team."

Francona said he had spoken to the players who could be affected by the acquisition of LaRoche. That included third baseman Mike Lowell, who has been bothered by a hip strain and didn't start Wednesday, and infielder Mark Kotsay, who returned from the disabled list June 2 after recovering from offseason back surgery.

"It's my responsibility to make it work really well," Francona said. "Then if something happens, we're not caught short."

LaRoche had 38 extra-base hits for Pittsburgh. Only Jason Bay and Kevin Youkilis, who both had 42 extra-base hits going into Wednesday's game, had more for Boston.

The Red Sox sent Class AA shortstop Argenis Diaz and Class A right-hander Hunter Strickland to Pittsburgh.