Fulham chiefs felt Dimitar Berbatov didn't have the stomach for a relegation battle.
The Bulgarian striker left Fulham for AS Monaco on deadline day last week.
The Daily Mail says when the Monaco option emerged because of a long-term injury to their top striker Radamel Falcao, Berbatov began to stamp his feet. Fulham felt there was little option, but to let him to leave.
His contribution had been limited, with just four Premier League goals in 18 appearances, and his application was waning.
Fulham's technical staff felt it was better to get rid of Berbatov as they prepared for the mother of all battles to beat relegation.
