Barnsley have announced head coach Gerhard Struber has left the club to take charge of Major League Soccer side New York Red Bulls.
Austrian Struber, 43, who has previously coached at Red Bull Salzburg, masterminded the club's escape from Championship relegation trouble last season.
Adam Murray will take caretaker charge.
"I must start by thanking Gerhard for the last 11 months. Tasked with maintaining the club's Championship status, he took a difficult position at Oakwell last November," said chief executive Dane Murphy.
"Despite the seven-point deficit and COVID-19, his belief never wavered and the night at Brentford will live long in the memory of all supporters.
"As much as we wanted Gerhard to remain at Oakwell we were not in a position to deny him this opportunity with a buy-out clause in his contract and his connection within the Red Bull set-up.
"Looking toward the immediate future, the recruitment process for a replacement has already begun and we will update supporters when appropriate. In the interim, Adam Murray will take charge of first team matters.
"This club has good people across numerous departments that will do their utmost to assist Adam."
New York Red Bulls, eight points off the play-offs in the Eastern Conference, sacked head coach Chris Armas last month.
Struber spent just 11 month at Oakwell after signing a two-and-a-half-year deal to replace German Daniel Stendel in November last year.
Barnsley were bottom of the table when Struber took over and after winning their last two matches survived relegation due to Wigan's 12-point deduction for going into administration.
Struber took previous club Wolfsberger into the Europa League and is reunited with the Red Bull franchise having coached various youth levels at Salzburg.
Following Barnsley's Sky Bet Championship defeat at Middlesbrough on Saturday, Struber questioned the club's ambition.
"For me, it's not the goal to always play in the relegation zone," he told BBC Radio Sheffield.
"I have other ambitions and aims and I cannot feel that the owners have the same ambitions and goals like me. My future is open and we will see.
"Every year, every season, this is a big, big fight with a big, big energy until the last game to stay in the league – and, one more time, it is a big question to the owners, is this the goal? For me, no."
Barnsley have taken one point from their first four league games and sit just above the bottom three.
"I am looking forward to getting to know my new team, hopefully very soon," said Struber after being announced by New York.
"We want to pursue very ambitious goals together and develop steadily. The challenge of working in MLS makes me proud and gives me massive motivation for a big opportunity."