Watford manager Walter Mazzarri will have to make a late call on the fitness of Italy international of Nigerian descent Stefano Okaka ahead of the Premier League clash with Crystal Palace on Boxing Day.<br /><br />The former Roma wonderkid only resumed light training this week after sitting out games against Manchester City and Sunderland due to a hamstring complaint.<br /><br />Prior to his spell on the sidelines, Okaka put up a man of the match performance, netting a brace in Watford&rsquo;s 3-2 win versus Everton at the Vic, the fifth time he wore the Hornets shirt in the Premier League. <br /><br />Nigerian pair Odion Ighalo and Isaac Success are both available for selection against the Eagles. <br /><br />Igho Kingsley <br />