#4. Chelsea: Striker

Chelsea have begun life under Mauricio Sarri with great aplomb, winning 5 and drawing 2 of their first 7 games in the Premier League, ending Liverpool's winning run most recently. Eden Hazard has been in fabulous form for the Blues, while new signings Kepa, Jorginho, and Kovacic have all impressed in the games so far.
The vertical tiki-taka system of Sarri seems to have put an attacking edge to Chelsea's playing style and with blistering wingers of the calibre of Hazard, Willian, and Pedro, Chelsea is armed with great pace and trickery, but they need a more reliable figure up top to convert the chances created by their wonderful wingers and their new midfield maestro Jorginho.
Alvaro Morata has started the season where he left of last season. The Spaniard cannot seem to find his confidence back and has continued his miserable run of form in front of goal. While Chelsea can also call upon the services of World Cup winner Olivier Giroud in the same position, neither can guarantee them with 25-30 goal seasons that other top strikers offer their teams.
As for alternatives, Chelsea can choose to call back Belgian striker Michy Batshuayi who seems like he could be a good fit in the Sarri system. Batshuayi recently became the first person in this century to score in the Ligue 1, the La Liga, the Premier League and the Bundesliga. He has been a consistent goalscorer everywhere he has played and deserves a chance at Chelsea under Sarri.
Looking aside that option, Chelsea should ideally look to spend big and make an attempt to make a marquee signing such as a Mauro Icardi or a Robert Lewandowski to show their statement of intent to return to the top of their game and challenge for the Champions League under Sarri rather than looking for another experimental option up top to spearhead their charge.