Alvaro Morata will undergo further tests on a hamstring injury which is threatening to derail his season as Chelsea bid to learn the full extent of the fitness setback which forced him out of the Premier League defeat to Manchester City. The 24-year-old has a grade two myofascial problem but the length of his absence has yet to be confirmed, despite reports he could miss upwards of six weeks of action.

The former Real Madrid hitman has withdrawn from the Spain squad for the upcoming World Cup qualifiers against Albania and Israel and returned to the Blues' Cobham training base to be assessed. ESPN understand the English champions hope to decipher for how long they will be without their top scorer this week.

Chelsea boss Antonio Conte has suggested the injury suffered by Morata – who was replaced 35 minutes into the 1-0 defeat to City at Stamford Bridge – is not "serious" despite indications he could miss up to nine games for club and country, including the visit of Manchester United in November. Morata used his various social media accounts to clarify his fitness on Tuesday [3 October] and suggested he could return for the resumption of the domestic season against Crystal Palace on 14 October.

But it remains to be seen whether Morata will indeed return after the international break. Conte could turn to Michy Batshuayi, who has scored five goals already this season, or Willian to replace Morata after the Brazilian winger came on for him at the weekend. Should the initial six-week prognosis prove to be accurate then it will represent a major blow for Chelsea, who have seen their record signing score eight goals in nine games this term.

As well as missing the climax to Spain's World Cup qualifying campaign, Morata would likely sit out seven games for Chelsea starting against Palace at Selhurst Park. Three home games in a row follow in three different competitions with Roma in the Champions League, Watford in the Premier League and Everton in Carabao Cup all travelling to west London in October.

Trips to Bournemouth and Roma follow before Jose Mourinho's United take on the defending champions on 5 November, prior to the final international break of the year. But should Spain take four points from their final two qualifiers and secure direct passage to Russia 2018 this month then Morata is unlikely to be required.

Alvaro Morata
Morata is hopeful of being out for just two weeks - but a longer absence beckons. Getty Images