Henderson was booked for the 10th time this season in the 1-1 draw at Plymouth last weekend and begins a two-match suspension as the Hornets go in search of a first win in eight games.

That should see Nathan Ellington return to the starting XI alongside Collins John in attack - despite neither finding the net since Ellington's goal at Ipswich on February 9.

John Eustace is also banned for a second game. The midfielder was sent off against his former club Stoke recently and had his three matches extended to four after he was found guilty of failing to leave the field of play in a timely manner.

Former Wigan midfielder Damien Francis (knee) is still out while Gareth Williams is expected to miss the rest of the season after suffering a reccurrence of a cruciate knee ligament injury.

Boothroyd's men remain just three points off the top of the Championship table despite drawing seven matches in a row.