The South American striker had a deal in place to depart Real Betis for the remainder of the season, however Boca's lack of interest ensured he staying in La Liga.
The 30-year-old switched from Villarreal to the Estadio Manuel Ruiz de Lopera outfit last August, but has failed to hold down a regular place netting just twice all season.
"I decided to buy Martin's transfer and offer him to Boca on loan," explained Mascardi. "Boca had the chance to sign him but they didn't do it, so Martin will stay at Betis.
"I spoke about this opportunity with the player but he wasn't sure because no one from Boca really offered him anything.
"I decided to get him out of Betis and he was going to arrange everything with the officials of the Spanish team, but Boca weren't really interested.
"It would had been a problem if Martin arranged everything with Betis, I bought his transfer and then Boca didn't want him because he wouldn't have had a club to train with over the next six months."
