On July 5, 2025, the Philadelphia Union signed homegrown midfielder Sal Olivas and defender Neil Pierre to short-term agreements ahead of their match against Nashville SC.

This call-up marks the second time Olivas has been called up in his MLS career, following his debut match against Columbus Crew.

Neil Pierre, who stands 6 feet 5 inches tall and weighs 176 pounds, was born on October 19, 2007, in Lebanon, Pennsylvania, and is making his seventh call-up for the club this season.

As off-roster Homegrown Players, both Olivas and Pierre can participate in up to six MLS League matches per season, provided they are 21 years old or younger during the calendar year.

Despite his multiple call-ups, Pierre has yet to appear in a league match, reflecting the competitive nature of the team's roster.

Eddy Davis III, a forward born on June 17, 2006, in Los Angeles, California, is also making his second call-up in 2025.

This latest call-up marks the eighth for the Philadelphia Union in 2025, highlighting their reliance on young, off-roster players.

The three players are eligible to participate in the match as short-term call-ups, in accordance with the 2025 MLS Roster Rules and Regulations.

Players who are off-roster Homegrown must be 21 years old or younger during the calendar year to qualify for this status, which applies to both Olivas and Pierre.

Olivas is categorized as an off-roster Homegrown player, making him eligible for short-term call-ups, but ineligible for regular MLS League Season competition.

This signing comes as part of the Union's strategy, as they had previously signed three off-roster Homegrown players, including Eddy Davis III, for their match against Columbus Crew on June 29, 2025.

Sal Olivas, born on July 11, 2006, in El Paso, Texas, is receiving his first MLS call-up, showcasing the Union's commitment to developing young talent.