Adomah, 21, who joined the Bees from non-league Harrow Borough in 2008, has been linked with the liks of Plymouth after bursting onto the scene with 14 goals in 67 appearances in League Two.
Gunn has also been linked with Simon Whaley of Preston, although Alan Irvine has ruled out a swap deal involving Darel Russell. Jason Demetriou of Leyton Orient is another name reported to be in the wide man frame.