Benfica footballers Julian Weigl and Andrija Zivkovic were reportedly hospitalised after being hit with stones while travelling in the team bus on Thursday.
The attack comes in the aftermath of Benfica drawing their Premiera Liga match against lowly Tondela.
According to The Sun, some Benfica supporters weren't happy with the team's performance in their first game back after the coronavirus pandemic had halted the season in March.
The report also stated that coach was attacked on a stretch of motorway between Benfica stadium Estadio de la Luz stadium and their training facility.
'Sport Lisboa and Benfica denounce and lament the criminal stoning the bus of its players was victim to,' the club statement read.
'We guarantee total collaboration with authorities to whom we appeal for the greatest effort to be made in identifying the delinquents responsible for these criminal acts.
'We inform that, as a matter of precaution, players Julian Weigl and Zivkovic were immediately taken to Hospital da Luz to be observed, following the shrapnel that hit them,' it added.
( With inputs from IANS )