Town will receive 20% of any profit Charlton make on Darren Bent if they decide to sell him, according to a report. The striker has made a huge impact since returning to the Premiership this season and has been linked with a number of clubs, including Liverpool and Spurs, at fees in excess of £6 million.
The Blues negotiated the clause when the frontman joined Charlton in June 2005 and will also gain £100,000 from each of his first two competitive appearances for England.
Town received £50,000 when the 22-year-old played his 20th game for the Addicks and will net another £50,000 when he reaches 40, probably at the weekend.
Meanwhile, Kilmarnock are the latest club to be linked with released striker Dean McDonald. The former Arsenal trainee is expected to join the SPL club on trial. The 20-year-old is also set for a spell at Watford.
Kevin Horlock is expected to return from his two-month loan spell with Doncaster before Monday's game at Watford. The former Northern Ireland international has failed to agree a longer-term deal with the Earth Stadium club. Horlock has been linked with a summer move to a club in New Zealand.
Cathal Lordan played for Bradford's reserves against Rotherham this week as he continues his trial with the Bantams.
Boss Colin Todd says the Irish youngster, told he has no future at Town after the end of the season, was recommended by his Town counterpart: "I spoke to Joe Royle about who he might be releasing and he said he had a midfielder who he thought could do somebody a job, so we decided to have a look at him."