The Red Sox obtained pitcher Jason Johnson on Wednesday, a day after the right-hander was designated for assignment by the Indians. The Red Sox, beset by injuries to starting pitchers, gave up a player to be named or cash for Johnson, who is 1-8 with a 7.38 ERA in his last 10 starts. Johnson, signed in the offseason after two years with Detroit, is 3-8 this season and has allowed 10 homers and 108 hits in 77 innings.