According to The Athletic, the 18-year-old forward suffered a grade-four injury which means he is not only unavailable for Chelsea for the rest of the season but he could also be absent from the World Cup.
Estevao has an impressive first campaign for the Blues, registering eight goals and four assists in 36 matches under multiple managers at Chelsea who have been incredibly inconsistent this season.
The winger pulled up during Saturday's defeat to Manchester United and manager Liam Rosenior admitted that the Brazilian cried when taken off the pitch.
"He was crying at half time; it was really devastating for him. It looks like it's his hamstring and that has happened in a moment when he's running through on their goal for a one-v-one chance – he pulls his hamstring in that moment.
“I hope Este comes back sooner rather than later."
Estevao's absence is a significant blow to Chelsea’s attacking options which were already hit hard against Brighton as both Cole Palmer and Joao Pedro missed out in the 3-0 defeat.
Chelsea have lost and failed to score in each of their last five league games for the first time since 1912. Now, without Estevao, things could go from bad to worse for the side as the winger aims to recover before the start of this summer’s tournament.