Benfica duo Julian Weigl and Andrija Zivkovic have reportedly been taken to hospital after the Portuguese club's bus was stoned by angry supporters, according to A Bola.
Benfica were held to a 0-0 draw at home to Tondela in their first game back since the coronavirus pandemic shutdown, missing out on the chance to leapfrog Porto at the top of the Primeira Liga.
And their fans reacted to the result by attacking the team bus in unsavoury scenes.
Reports say that Weigl and Zivkovic were both struck in the face by shards of glass from the bus' windscreen after it was pelted by rocks.
The two players were treated near the club's training centre before being taken to Hospital da Luz as a precaution.
Benfica were in action for the first time in three months and Porto's 2-1 defeat to Famalicao on Wednesday gave Bruno Lage's side the chance to move into first place.
Inside the Estadio da Luz stadium, thousands of Benfica scarves were placed on the seats to represent supporters, while the eagle mascot made its traditional pre-game flight.
Benfica dominated their opponents from the start, creating more than 20 attempts and hitting the woodwork twice near the end.
However they were unable to find a way through and had to settle for a point.
The draw leaves Porto and Benfica tied with 60 points at the top of the table with nine rounds remaining.
"They always played with 10 men behind the ball, it was tough," Benfica midfielder Adel Taarabt said, per the Daily Mail.
"We kept trying and trying but the ball just wouldn't go in. Of course we missed our fans, but that can't be used as an excuse."
It was Benfica's third consecutive draw and clearly the fans were not happy with it.