Red Sox reliever Bobby Jenks, who was being treated for a lower back problem, was recently diagnosed with a small pulmonary embolism. Jenks is receiving medication for the blockage of the lungs, and the Red Sox expect him to make a full recovery. His season is over. "This was a very small - I mean, this is still nothing to mess around with - but it's a very small embolism. They have it under control," manager Terry Francona said. "Certainly, they want it to go away, but I think they feel that he's in good shape." Jenks signed a two-year, $12 million contract with the Sox last winter. He has made three trips to the disabled list for a right biceps strain and back tightness, and hasn't pitched since July 7.