Veteran frontman Geoff Horsfield, a free agent after being released by Lincoln, has emerged as a possible contender, but while Adams has admitted to having contact with the 35-year old he has refused to confirm whether he has been offered the job.
Adams had previously favoured Chesterfield's Robert Page, who was his captain during his time at Coventry, but the defender has opted to see out the last year of his deal with the Spireites.
Speaking to The Sentinel, Adams revealed: "We are in negotiations with somebody. At the moment we can't agree terms and we are still negotiating. Nothing is dead yet and there is no timescale on it."
Adams is currently being helped with his pre-season duties by youth-team manager Mark Grew.
"Now pre-season has started I have a heavy workload, but I have Mark assisting me and he's been excellent," added the Vale boss.