adidas +F50i Tunit

The +F50i Tunit succeeded the F50.9 Tunit in Messi's rotation in May 2009 and represented the most significant technological leap of the TUNiT era, introducing SprintSkin, adidas's first ultra-thin single-layer synthetic upper. It's also the boot behind one of the most iconic single images of Messi's career: him holding his boot aloft in celebration after it came off during his header goal in the 2009 Champions League final. He wore it through the rest of Barcelona's historic sextuple-winning run and into his first Ballon d'Or (FIFA World Player of the Year) win in December 2009.

• 27 May 2009: Messi becomes the first player to officially debut the new +F50i Tunit in a match, wearing it in the UEFA Champions League final against Manchester United at Rome's Stadio Olimpico, in a Cyan/Running White/Black colourway.
• June 2009: The +F50i Tunit launches at retail (around $195 in the United States), through adidas Sport Performance stores and specialty soccer retailers, with a White/Black colourway following shortly after in August 2009.
• 6 June 2009 onward: Other elite adidas-sponsored players adopt the F50i during 2010 World Cup qualifying matches.
• 2009–10 season: Messi wears at least two dedicated colourways: a "Navy/Gold/Argentina Blue" edition with a K-Leather upper and lace-cover graphics referencing the flags of Argentina and his hometown of Rosario, and a later "White/Navy/Gold" edition released around a Clásico fixture, timed to coincide with his first FIFA World Player of the Year win in December 2009.
• June 2010: Messi transitions away from the TUNiT platform entirely into the newly launched F50 adiZero ahead of the 2010 World Cup, closing out the TUNiT era of his career.

Represented the most significant technological leap of the TUNiT era. Its headline innovation was SprintSkin, a proprietary single-layer, ultra-thin synthetic upper (reportedly the first football boot upper of its kind), designed to function like "a second skin": supple, lightweight, and water-repellent, while aiming to preserve the boot's overall fit and touch despite the reduced material. The F50i retained TUNiT's customizable studs and chassis options and used an ergonomic, thermo-bonded lace structure. Commentary from the period frames the F50i as adidas's clearest signal yet that it was moving toward the ultra-minimal, second-skin construction philosophy that would culminate the following year in the sub-200-gram F50 adiZero, which abandoned the interchangeable TUNiT system entirely in favour of a fixed, ultra-light build.

Messi's Champions League final pair was a striking Cyan/Running White/Black combination, distinct from the standard team colourways worn by other players. Later in the 2009–10 season, adidas released two explicitly identity-driven colourways for him: a Navy/Gold/Argentina Blue edition using premium K-Leather with custom lace-cover graphics referencing both the Argentine national flag and a symbol tied to his hometown of Rosario, and a White/Navy/Gold edition released to coincide with his first FIFA World Player of the Year award.

adidas's marketing leaned directly into Messi's Argentine identity with the K-Leather F50i colourway referencing the Argentine flag and his hometown of Rosario, an early example of the kind of personal, heritage-driven storytelling that would become a defining feature of adidas's Messi campaigns for the rest of his career (later repeated, for instance, in numerous "Rosario" and "Pibe de Barr10" themed boots in subsequent years). The F50i's SprintSkin technology was also positioned by adidas as the clear evolutionary bridge between the bulkier, more experimental TUNiT era and the ultra-light "second skin" design language that would define its speed boots for the following decade, with Messi as its most visible showcase athlete.

• 27 May 2009: UEFA Champions League final, Rome. Barcelona beat Manchester United 2–0. Messi, deployed as a false nine, rises to head in Barcelona's second goal in the second half, one of the defining goals of his career; in his goal celebration his F50i Tunit boot came off, producing an iconic image of him holding it aloft, and this match also marked Messi's first official appearance in the F50i, worn in its Cyan/Running White/Black colourway.
• 28 August 2009: Barcelona beat Shakhtar Donetsk 1–0 in the UEFA Super Cup, extending the trophy haul.
• August 2009: Barcelona win the Spanish Super Cup over Athletic Bilbao (1–2 away, 3–0 at home), with Messi scoring twice in the second leg.
• 19 December 2009: Barcelona beat Estudiantes de la Plata 2–1 after extra time in the FIFA Club World Cup final in Abu Dhabi, completing the historic sextuple.
• 1 December 2009: Messi wins his first Ballon d'Or (then still contested as FIFA World Player of the Year in this specific form), beating reigning winner Cristiano Ronaldo by a then-record 240-point margin, with Xavi finishing third, becoming the first Argentine-born winner since Omar Sívori in 1961 (who had by then taken Italian citizenship).

The F50i is the Tunit worth remembering: it introduced SprintSkin, adidas's first ultra-thin single-layer upper, and it produced one of the defining images of Messi's career: the boot held aloft after his header in the 2009 Champions League final in Rome. Contemporary testers loved the ball feel from the thick K-leather but knocked the shapeless initial fit, and forum users of the day rated it behind Nike's Vapor for comfort and durability. As the bridge between the modular TUNiT experiment and the adiZero revolution (and the boot of the sextuple and Messi's first Ballon d'Or), it's the most collectible Tunit by some distance, especially the Argentina-flag K-leather colourway.