According to the Hereford Times, Bevan had been offered revised terms following the club's fourth-place finish in the Midland Football League Premier Division, but was unable to accept them.
Westfields also lifted the HFA County Challenge Cup after thrashing Pegasus Juniors 6-0 in the final.
The news comes on the back of allpay Ltd deciding not to renew their sponsorship of the club.The Whitestone-based firm had been Westfields' main sponsor for the past 15 years.