The Red Sox placed second baseman Mark Bellhorn on the 15-day disabled list with a sprained left thumb and recalled infielder Kevin Youkilis from Triple-A Pawtucket. Bellhorn was injured diving for Jason Giambi's grounder in the fourth inning of Sunday night's game against the New York Yankees. Bellhorn is batting .216 with 20 doubles, seven homers and 28 RBI. He leads the major leagues with 109 strikeouts. Youkilis hit .286 with one homer and nine RBI in 26 games over two previous stints with the Red Sox this season.