It is understood that Hornets head coach Rob Edwards is keen to take a look at all of the club’s players before making decisions regarding moves.
Zinckernagel’s current loan deal at the City Ground is set to expire tomorrow.
The winger helped Forest achieve promotion to the Premier League by producing some impressive performances for the club in the second-tier last season.
Forest sealed a place in the top-flight on Sunday as they sealed a 1-0 victory over Huddersfield Town in the play-off final at Wembley Stadium.
The Reds are believed to be keen to reach an agreement with Watford over a deal for Zinckernagel.
Whereas the 27-year-old is now set to go on holiday, his representatives will remain in contact with Watford and Forest.
Zinckernagel’s current deal at Vicarage Road is set to run until 2026 and thus the Hornets could secure a significant for him this summer if they are willing to sell him.
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When you consider that Watford opted against giving Zinckernagel the chance to impress in the Premier League last season, it wouldn’t be at all surprising if the winger wants to test himself at this level by moving to Forest.
Having provided 19 direct goal contributions in 65 Championship appearances during his career, there is a chance that Zinckernagel could become a key player for the Hornets if the club opt against cashing in on him.
Given that Watford unquestionably need to strengthen their squad defensively after conceding 77 goals in the top-flight in the previous term, selling the winger could help to facilitate moves for new players.
The Hornets ought to be looking to make a decision regarding Zinckernagel’s future relatively quickly as it will give them more time to focus on other areas that they need to address ahead of their return to the Championship.