Brown, 22, had a strong season in Germany, scoring four goals and contributing four assists across 33 Bundesliga appearances, 29 from the start.
The Germany international is expected to leave Frankfurt this summer, and Arsenal face competition from multiple clubs including FC Bayern München for his signature. Frankfurt are seeking in the region of €65m.
Valdepeñas is a different proposition — a 19-year-old from Real Madrid's academy who plays primarily as a centre-back but is comfortable at left-back, and is seen by Arsenal as a versatile long-term option on the left side of the defence.
The Spaniard made his senior debut for Real Madrid in December 2025 before losing his place following the departure of Xabi Alonso in January. He is contracted at the Bernabéu until 2029 with a reported release clause of €50m, and Eintracht Frankfurt have also been pursuing him.
The Athletic report that manager Mikel Arteta's recruitment priority this summer is the left side of the attack, but the defensive need is running concurrently. Both Brown and Valdepeñas are understood to be genuine rather than peripheral targets.
Arsenal are in strong financial shape following a season in which they won the Premier League title for the first time in 22 years, and Arteta has made clear the club intends to spend ambitiously to close the gap on PSG.