Marco Silva has been appointed Watford's new head coach following the departure of Walter Mazzarri. Press Association Sport looks at some of the things the Portuguese has to do as the ninth man in charge in five years.WORK OUT WHAT THE POZZOS WANTThe manager's office at Vicarage Road has had a revolving door in recent years as the owning Pozzo family have been quick to dispense with head coaches who have not met their expectations. Last season Quique Sanchez Flores kept them up and took Watford to an FA Cup semi-final but was still sacked. Mazzarri avoided the drop this time around but went all the same. Silva has to find a way to keep the owners happy if he wants to last longer than most of his predecessors.UPGRADE THE SQUADSix successive defeats saw the Hornets limp towards safety, finishing 17th, and there are reinforcements required in all departments. Four of the existing six centre-backs will be over 30 by the start of the new season. They managed just four goals in their last eight matches - three of which came in one match - with Troy Deeney (10) and Etienne Capoue (seven) the only players to score more than four league goals all season.MAKE WATFORD MORE COMPETITIVEThe team has regressed after finishing 13th with 45 points - eight clear of the bottom three - in the previous campaign. They conceded three or more goals in in almost a quarter of their matches this season, lost 20 matches and took 12 points from a possible 57 away from home.