The Premier League has already presented plenty of surprise moments during the opening five Gameweeks of the new season and the most notable one came last weekend where Norwich City bagged a shock 3-2 triumph over reigning champions Manchester City. Here are some things to watch for during the upcoming Gameweek.Manchester Citys central defence: The Citizens saw the central defensive pairing of John Stones and Nicolas Otamendi concede three times at Carrow Road. Since then, Stones has been sidelined with a thigh problem for a month Jeff Bagwell Jersey and this means Otamendi remains the only fit senior centre-back available with Aymeric Laporte also sidelined following a knee surgery. Carlos Correa Jersey Fernandinho did an efficient job as the makeshift centre-back alongside Otamendi in the midweek Champions League game against Shakhtar Donetsk which ended 3-0 in the clubs favour and it will be interesting to see whether the duo can provide a similar level of performance against Watford. The constant change at the heart of the defence has not aided the clubs defensive record and they have kept just from the opening five Premier League matches.Mason Greenwood and Bukayo Saka: The midweek Europa League action saw a couple of young graduates in Mason Greenwood and Bukayo Saka hit the headlines. Greenwood made his first start of the season for Manchester United against Astana and he made the difference by scoring the in the 73th minute. On the other hand, Saka was handed with his first appearance of the campaign against Eintracht Frankfurt and the Arsenal youngster stepped up to the plate with a stunning display of his Anthony Gose Jersey own. The teenager was lively with his dribbling and direct running, and capped the performance with from Mike Scott Jersey outside the box. It remains to be seen whether the youngsters are rewarded with starting roles for the weekend on the back of scoring their maiden profe sional goals for their respective clubs.Liverpools Premier League winning streak: The Reds made it 14 league wins on the bounce last weekend after they picked up a 3-1 triumph over Newcastle United. That has included five victories on the trot this season which sees them at the top of the standings with a healthy five-point advantage over second-placed Manchester City. Up next, they are scheduled to face Chelsea on the road and the game could be a tricky one despite the fact that the Blues have po se sed a leaky backline. Frank Lampards side dominated the proceedings during the backend of the European Super Cup Gerrit Cole Jersey clash against the Reds last month where the latter . With the Blues po se sing the home advantage this weekend, Jurgen Klopps side are bound to face a strong test of their credentials particularly after the at Napoli in midweek.