BoSox deal Scutaro to Rocks, eye Oswalt

The Boston Red Sox had a busy Saturday, trading shortstop Marco Scutaro and his $6 million salary to the Colorado Rockies while remaining in pursuit of free-agent starter Roy Oswalt.

The Red Sox may be the favorite to sign Oswalt, sources say. The Detroit Tigers were on the fringe of the Oswalt market as of Saturday evening. Other teams were involved, as well.

The Red Sox, who obtained right-handed pitcher Clayton Mortensen for Scutaro, are motivated to upgrade their starting rotation. The cost-cutting Scutaro trade is evidence they must do so while staying within a budget.

Oswalt went 9-10 with a 3.69 ERA in 23 starts and 139 innings with the Philadelphia Phillies last year. The 34-year-old landed on the disabled list twice in 2011 because of back injuries. He has never pitched for an American League franchise.

Left unresolved — for now — is who will play shortstop for Boston this year. After the trades of Scutaro and Jed Lowrie, Mike Aviles (six) and Jose Iglesias (one) are the only players remaining on the Red Sox roster who started games at shortstop in 2011.

Nick Punto, who joined the Red Sox as a free agent, started eight games at shortstop for the World Series champion St. Louis Cardinals last year.