The 29-year-old only moved to Vicarage Road in January after the Hornets paid Atletico Madrid around £3m.
The Spaniard impressed during the second-half of last season, but he is seemingly not in the plans of new boss Walter Mazzarri.
And, according to Plaza Deportiva, Suarez is closing in on a return to Spain after agreeing terms with Valencia.
The La Liga side have offered the central midfielder a four-year deal and he has verbally accepted the proposal, reports claim.
Valencia are now trying to agree fee with Watford for the player and negotiations began today.