John Farrell is preparing to go into Opening Day without closer Koji Uehara.
Uehara felt discomfort in his hamstring while throwing in the bullpen on Saturday, a throwing session that was supposed to be the last step before he got into a Grapefruit League game. Instead, the Red Sox will back off Uehara, giving his hamstring another day or two of rest and rehabilitation before he tries to throw another bullpen.
Uehara originally strained his right hamstring on March 17 while doing conditioning drills in Red Sox camp. He obviously pushed it a little too hard in his rehab and will now presumably open the regular season on the 15-day disabled list. Edward Mujica is likely to get the early-season save opportunities for Boston.
Uehara has fantastic career numbers in the United States, but he gave up 10 earned runs in his final 7 2/3 innings last season and he turns 40 years old just before the beginning of the 2015 campaign.