Terry Francona was distracted by marital issues and his use of pain medication last season, a team source told the Boston Globe, an allegation the former Red Sox manager denied.
"It makes me angry that people say these things because I've busted my (butt) to be the best manager I can be," Francona said when the Globe presented him with its findings. "I wasn't terribly successful this year, but I worked harder and spent more time at the ballpark this year than I ever did."
Francona's eight-year tenure with the Red Sox came to an end earlier this month in what was called a mutual decision.
The team declined to exercise an option on Francona's contract following the Red Sox's historic September collapse in which they went 7-20 and failed to make the playoffs.
Francona, married to his wife, Jacque, for almost 30 years, moved out of their house and lived in a hotel this past season, the newspaper reported.
According to the Globe, team sources also had concerns that Francona's performance may have been affected by his use of pain medication.
Francona, who has had nearly 20 surgeries on his knees, has used pain medication for many years. He told the newspaper he used painkillers after knee surgery in October 2010 and used them during the season to relieve the discomfort after doctors drained blood from his knee at least five times.
Francona told the newspaper that he consulted with the team's internist, Dr. Larry Ronan, during spring training after one of his children expressed concern about a pill bottle in his hotel room.
"I went and saw the proper people and it was not an issue," Francona said. "It never became an issue, and anybody who knew what was going on knows that.''
Reached by ESPNBoston.com on Wednesday, he said he would have no further comment.