The shot-stopper is suspected of having been in touch with a murder suspect, and was detained after the match versus Newell's Old Boys
The 31-year-old was held by police immediately after San Lorenzo's 1-0 loss against Newell's Old Boys on Sunday.
"San Lorenzo would like to inform that due to a request from judge Manuel de Campos, Pablo Alejandro Migliore has been held up as part of an ongoing investigation of a supposed homicide cover up," an official club statement reads.
Migliore is suspected of having ties with Boca Juniors 'barra brava' member Maximiliano Mazzaro, who is a fugitive suspect in the murder of Ernesto Cirino.
The goalkeeper wore the Boca jersey from 2005 until 2008.