The Spaniard has already served as an assistant and was at the helm in previous two stints.
The club parted ways with Jose Manuel Diaz last month and Renedy Singh took over as interim head coach.
Spaniard Rivera guided East Bengal to a second-place finish in the I-League two seasons back. A UEFA Pro Licence holder, Rivera, in a matter of just seven matches took them to the second position.
“We are happy to appoint him as our head coach. Mario has been part of East Bengal previously and his experience in Indian football will be beneficial to the team for the rest of the season,” SC East Bengal CEO Col. Shivaji Samaddar said.
Rivera has worked with former East Bengal coach Alejandro Menéndez as his deputy for 32 games in 2018-19 season before he was asked to take over the reins. Rivera will undergo the mandatory quarantine period as per ISL and will take over thereafter.
SC East Bengal in ISL 2021-22
The Red and Golds are yet to win a match in ISL 2021-22. So far they have played eight games and drawn and lost four each. Their latest draw against Hyderabad FC was followed by previous head coach Manolo Diaz stepping down from his position. Assistant coach Angel Puebla Garcia has also left the club. SC East Bengal are currently at the bottom of the 11-team league with only four points. Their season already looks over with playoffs now a distant dream.
The club will take on Bengaluru FC at the Athletic Stadium in Bambolim on Tuesday. With Rivera expected to undergo full quarantine as per ISL norms, Renedy Singh, who is the caretaker manager, is likely to be in charge of that game.