That means one of Gray or Okaka will get the nod at Goodison Park against the managerless Toffees.
In reality it is a straightforward decision for Silva. Okaka has not played since scoring in the 3-3 opening-day draw with Liverpool. The burly Italian has only been included in the matchday squad once since, in fact.
The other big doubt is over the fitness of Roberto Pereyra. The Argentine missed last weekend’s game against the Potters with Silva re-introducing Étienne Capoue. The Frenchman could start once more with Tom Cleverley pushed on to No.10.
The Hornets have a number of long-term absentees and are without Isaac Success (knee), Nathaniel Chalobah (knee), Younès Kaboul (hamstring), Sebastian Prödl (knee), Craig Cathcart (knee) and Tommie Hoban (knee).
Our unique algorithm has predicted the Watford side it believes is most likely to start, but you can also give it a go yourself.
Just click ‘create your own’ on the lineup at the top of the page and pick the XI players you would choose, and you can also see their stats per 90 minutes once you’ve picked them.
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