Nuno's managerial future with Valencia will reportedly depend on how the Spanish club fare in their next three fixtures.
The 41-year-old took charge of Los Che last summer and was widely lauded for his work while leading the team to a fourth-place finish in the La Liga table.
A bitty start to the new campaign has seen Valencia win just two of their seven league games, however, and according to Super Deporte, the club's next three fixtures will be decisive.
This weekend, Valencia will host struggling Malaga in the league, before continuing their Champions League campaign at home to Gent next week.
The third game sees Valencia travel to Atletico Madrid and while winning that match is not seen as vital, the team's performance will reportedly be considered.
Nuno has received whistles from a section of Valencia supporters this season.
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