Cerro fans threw objects at visiting Brazilian side Fluminense and Argentine referee Hector Baldassi after their team lost 1-0 in the first leg of the semi-final in the South American equivalent of the Europa League two weeks ago.
The referee, his linesmen and the Fluminense team had to wait more than 20 minutes in the middle of the pitch at the General Pablo Rojas stadium, also known as Olla Monumental, until they were able to leave the field.
The CSF said in a statement that Baldassi and the fourth official "reported the throwing of a great number of projectiles onto the field of play ... creating danger to the physical integrity of the visiting players."
The ban covers matches in South American club competitions.
Cerro had only just finished serving a previous South American ground ban following similar incidents early last year when they also paid a $20,000 fine, then the maximum punishment.
The CSF must now also rule on a brawl between Cerro and Fluminense players and coaching staff at the end of the last week's second leg at Maracana in Rio de Janeiro which Fluminense won 2-1 to reach the final 3-1 on aggregate.
This time no fans were involved but Cerro appear to have been provoked into fighting with the "Flu" bench after the Brazilians scored two stoppage time goals when the match, almost over with Cerro 1-0 ahead, looked set to go to penalties.
There is no extra time in the competition.
The CSF's executive committee meets again at their Asuncion headquarters on Wednesday.
