Plenty were surprised when it was Emery, most recently of Paris St Germain, who was selected following a rigorous interview process headed by former chief executive Ivan Gazidis.
Gracia has guided Watford to 10th place in the league but are in position to finish as high as seventh.
"When the possibility opened to sign here, the first coach, the first person in the football world I called was him", Emery said.
Asked if poor results away from home were due to a psychological problem, the Spaniard replied: 'But we are fourth at the moment and we are playing to be in the top four. We spoke about football here, English football and their experience because they were here six months before us.
"It was a good conversation about football because Javi Gracia is also a football man".
"They are my friends, not only Javi Gracia but also his assistant Zigor Aranalde and Inigo Arteaga". Yes, it's much better, the coach is relaxed, we know that when we have to train, we train, but when the training ends, we relax, we laugh.
Arsenal may have just £40m to spend if Emery fails to deliver Champions League football this season.
Unai Emery is positive about the side's chances for a top-4 finish, though.
A match against Arsenal in the Premier League looms, as Watford take on the Gunners on Monday, and Gracia says Deeney's character and ability are key to the club going forward.
"I think we are showing we are competitive and have a good mentality", Emery said.
"He's in a very good moment now, but it's not my decision and I always try to be respectful with the national team".
'This team have a good mentality and they are improving, we are improving and the table is giving us this answer - we are improving.