The Sporting Lisbon winger has vowed to give "1000%" to succeed at Elland Road.
Sacko became Garry Monk's third signing as Whites manager when he joined on a season-long deal from the Portuguese side, following the arrivals of striker Marcus Antonsson and defender Kyle Bartley.
Leeds have the option to make the deal permanent next summer if the 23-year-old winger impresses in English football, and if he performs then the former France youth international could certainly be a player to get fans excited this season.
Sacko has impressed for Sporting's B team in Portugal, and enjoyed a successful second half of last campaign on loan at French side Sochaux.
The player himself clearly cannot wait to get started at Elland Road, and has already made a pledge to supporters after signing terms with the Championship club.
Very excited to be part of this new chapter of @LUFC . I'll give my 1000% to succeed here ⚽❤— Sacko (@miimosaa) July 5, 2016
He wrote on his Twitter account: "Very excited to be part of this new chapter at LUFC. I'll give my 1000% to succeed here."
Though it is still day one, Leeds fans are likely to be pleased with that sentiment from their new man as they look to build upon another underwhelming campaign last term.
With Sacko adding to the arrivals Antonsson and Bartley, Monk has now strengthened his defence, wide midfield, and attacking options already this window, and the optimism from Whites fans that something better might be aroudn the corner is likely to continue with the latest signing.