San Lorenzo, 10 times champions and one of Argentina's so-called 'Big Five' clubs, became more entrenched in the relegation zone with a humiliating 4-1 defeat at Lanus on the opening day of the Clausura championship on Friday.
After a junior squad practice on Tuesday at the training complex on the edge of Buenos Aires and across the road from a dangerous "villa miseria" (shanty town), young players became involved in an argument with a group of teenagers who had just been to martial arts practice at the club, media reported.
Nicolas Salazar, a promising 15-year-old centre-back, was stabbed in the stomach during the fighting.
He was rushed to hospital where he is out of danger as no vital organs were affected, the daily La Nacion and sports newspaper Ole reported doctors as saying on Wednesday.
"This situation can't go on, what's happening in the club is very complicated," juniors coach Claudio Biaggio, a former first team striker, told La Nacion.
Local Bajo Flores district mayor Sergio Costantini told reporters: "This situation cannot be tolerated any longer, every day something [bad] happens at San Lorenzo."
Newspaper columnists are asking how someone can smuggle a knife into a club which has a police presence only four months after a member of a San Lorenzo 'barra brava' hooligan gang hit first team defender Jonatan Bottinelli in an argument over the team's failings in the Apertura championship.
Relegation has become the major topic of discussion on television and radio football chat shows with pundits pointing out that 'the Saints' appear not to have learnt from River Plate's bad experience when they failed to strengthen their squad a year ago and were relegated for the first time in June.
Relegation in Argentina is decided over three seasons. There is a separate table from the championship standings with the three-season points averages of the teams. The last two go down while San Lorenzo are three from the bottom in a play-off berth.
If they stay there, like River Plate in June, they will have to play off against a team from the second-tier Primera B Nacional division for the right to remain in the top flight.
The averages were introduced in 1983, two years after San Lorenzo's first relegation, when River Plate would otherwise have faced the drop.
Only Boca Juniors and Independiente of the 'Big Five' have never been relegated.
