A second-half surge enabled the Union to defeat FC Cincinnati this week 4-2, while Canonneros edged past Cruz Azul 3-1 on penalties in a match which ended 2-2 after 90 minutes.
Match preview
Deadly counterattacking has propelled Philadelphia to this stage of the tournament, scoring four times in the final 45 minutes against Cincy.
Philly are averaging just 42.5% possession at the Leagues Cup this year but have made the most of their scoring opportunities, netting on four of their six targeted efforts on Tuesday.
Jim Curtin's men are unbeaten after normal time in six consecutive matches played across all competitions while finding the back of the net in seven successive games.
The Union have not lost a quarter-final fixture since the 2016 US Open Cup when the New England Revolution beat them 4-2 on penalties.
Since losing 2-1 versus Toronto in the middle of July, this team have won their last five matches when scoring the opening goal.
The Union have only suffered one competitive defeat at Subaru Park versus a Mexican opponent, losing 2-0 to Club America in the 2021 CONCACAF Champions League semi-finals, exiting that tie 4-0 on aggregate.
Mazatlan persevered despite another late defensive breakdown this week, converting their three penalty kicks after squandering a 2-0 lead in normal time.
In four Leagues Cup fixtures this year, the Mexicans have yet to concede a second-half strike, but they have not scored in the final 45 minutes of the knockout stage either.
Their run to the quarter-finals was unexpected, seeing as they were on a six-match winless run across all competitions before this tournament began.
They lost their opening game versus the New England Revolution (1-0), but this team have overcome adversity since then, claiming victory in three successive must-win affairs.
Victor Manuel Vucetich's men are unbeaten in 10 consecutive matches across all competitions when netting multiple times, winning six of those encounters after 90 minutes.
In 2024, Mazatlan have never gone unbeaten in four successive competitive fixtures, matching their longest run without a defeat this year with their shootout victory against Cruz Azul.
Philadelphia Union Leagues Cup form:
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Philadelphia Union form (all competitions):
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Mazatlan Leagues Cup form:
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Mazatlan form (all competitions):
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Team News
On Tuesday, the Union were again without Isaiah LeFlore, who is still recovering from a right knee injury that has kept him sidelined throughout the competition.
Tai Baribo continues to light up the scoreboard at this tournament, netting a brace versus Cincy and leading the tournament with five goals, with the other strikes coming from Quinn Sullivan and Mikael Uhre.
In their victory over Cruz Azul, Mazatlan were missing Hugo Gonzalez because of a muscle injury, while Lucas Merolla was back in the lineup for the first time since hurting his knee.
Bryan Colula and Yoel Barcenas scored in the final five minutes of the opening half in their previous encounter, while Daniel Gutierrez stopped two Cruz Azul penalties, enabling them to advance.
Philadelphia Union possible starting lineup:
Blake; Mbaizo, Glesnes, Elliott, Wagner; Martinez; Bedoya, McGlynn; Gazdag, Baribo, Uhre
Mazatlan possible starting lineup:
Gutierrez; Almada, Alvarado, Sanchez; Colula, Torres, Sierra, Escoboza; Amarilla, Rubio, Barcenas
We say: Philadelphia Union 2-0 Mazatlan
The Union know what to expect in a high-stakes game like this and we believe they have the overall quality needed to end the Cinderella run of Mazatlan this weekend.