Philadelphia Union's Paxten Aaronson set to sign for Eintracht Frankfurt - source

Philadelphia Union midfielder Paxten Aaronson is set to sign for Europa League champions Eintracht Frankfurt after the two clubs agreed a fee for the United States youth international, a source has confirmed to ESPN.

Aaronson, brother of Leeds United's Brenden Aaronson, is set to be transferred to the Bundesliga club for an initial fee of $4 million plus add-ons and a percentage of any future sale, pending completion of a medical and agreement of personal terms.

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Details of the transfer were first reported by MLS reporterTom Bogert.

Paxten Aaronson, 19, captured the attention of many after winning the Golden Boot and being voted as the tournament's best player at this summer's CONCACAF U-20 Championship, when he scored seven goals to help the U.S. qualify for the 2024 Olympics.

The New Jersey native came through the same Union academy system that produced his brother Brenden, who left Philadelphia for FC Salzburg in January 2021 before joining Premier League side Leeds this summer.

Paxten Aaronson made his MLS debut as a 17-year-old in May 2021 before scoring on his first start later that season.

Union head coach Jim Curtin has previously said that the younger Aaronson was "going to be really special," noting that "obviously there's good genetics in the family."

Aaronson has made a total of 39 appearances (eight starts) for Philadelphia, scoring four goals.

He is set to be a part of the Union team that take on LAFC in the MLS Cup final at Banc of California Stadium on Saturday.

Eintracht Frankfurt beat Barcelona, West Ham and Rangers en route to winning the Europa League last season. They have backed that up this campaign by qualifying for the Champions League knockout stages and currently sit fifth in the Bundesliga table.