McKennie has been heavily linked with a move to the Premier League. Southampton and Newcastle United were both keen according to ESPN sources, while Chelsea and Liverpool also showed interest earlier in the season.
Juventus arrived with a late move for McKennie, with new manager Andrea Pirlo a key figure in accelerating the process for the USMNT midfielder, sources told ESPN.
And while a deal has not been completed yet, sources say McKennie would love the challenge to play at Juve and he feels that, with Blaise Matuidi gone and Sami Khedira getting fewer minutes, he could have a real chance to play in Turin.
McKennie made 28 Bundesliga appearances for Schalke last term and scored three goals.
He will come in during a summer where Juve are looking to bring down the average age of their squad, with several of their key starters over 30.
Pirlo was named Juve manager as a replacement for Maurizio Sarri earlier this month and in his first news conference, he announced that striker Gonzalo Higuain is set to leave the club.
World Cup-winner Matuidi left the club this summer to join MLS side Inter Miami.
Information from ESPN's Tom Hamilton and Stephan Uersfeld was used in this report