The Hornets have been the shock side so far this season having won all four Premier League matches, including a 2-1 victory over Tottenham Hotspur on Saturday.
"Pre-season was class and everyone bought into it. Now we are looking so fit and so strong, we've been winning most of our games in the second half," he said.
"Javi is unassuming, he's calm and gets on about his business but shows you a lot of respect, as a person and as a footballer. He has his style of playing and for what we have in our team it fits us perfectly.
"He wants us to play a high tempo, pressing from the front, and when you add the physicality we have it is just a good recipe at the minute."