But when Arnautovic, fit again after three games out injured, began to get on the ball West Ham looked a totally different team, especially to the one which surrendered so meekly at Brighton last weekend.
"I thought we started really well".
"We haven't had the success we would like".
After a first half in which they looked nothing more than ordinary, Watford produced a spirited second half recovery - helped by West Ham's lack of midfield quality, poor finishing and few with the ability to support Marko the magician.
The left-back has joined on a free transfer until the end of the season, and is in contention to play against Watford at the London Stadium tomorrow. The supporters want more ups than downs. But we defended well enough.
'He told me the story about it.
"Against Bournemouth I scored a goal, I tried to play pretty well in the Cup [against Wigan last weekend] and, in the last game, against Crystal Palace, I tried to do my best".
Speaking to the club's official website, Sullivan said: "He's very hard working, I have seen him at ground watching players when he was at Everton, he puts a long shift in at the training ground".
"Hopefully it might not be the season but he has had a fix to his medial ligament and more than likely he will be out for most of the season, who knows, we might get him back before the end but probably not", Moyes said of the Spanish midfielder.
"I wouldn't be happy with him doing it on my watch".
"He's going to give us a boost inside the dressing room as well as out because he has two or three more years to give at a good level of football".
West Ham have won just one of their last five home games against Watford (D1, L3).