Beckett is experiencing soreness and stiffness after throwing 126 pitches on Sunday.
Red Sox beat writer Rob Bradford tweeted,
Valentine says on @WEEI Beckett sore from last outing. Says Beckett feels stiffness— Rob Bradford (@bradfo) May 2, 2012
Beckett, who has not reached 200 innings in three of the last four seasons, will miss the start Saturday but it is unclear as to how long he will be out.
Aaron Cook will start in place of Beckett on Saturday.
This has to alarm Red Sox nation, considering their pitching staff is already a bit weak. Beckett has pitched 32.1 innings this season and has allowed 16 runs. He has already allowed seven home runs this season.
However, he has been much better since his first outing in which he allowed seven runs. If Beckett misses significant time, this will be a big blow to Boston.