U.S. international Christian Pulisic has extended his contract at Borussia Dortmund by a year, tying him to the club until 2020.
Arjen Robben, 33 on Monday, celebrates his birthday a Bayern Munich legend -- a remarkable turnaround from his annus horribilis back in 2012.
"We decided to go with Christian Pulisic, because he is a specialist wing player who has a lot of pace," Tuchel said.
"He will need a bit of time," Eintracht Frankfurt coach Niko Kovac said of the playmaker's injury.
Isak became the youngest player to ever score for Sweden when he struck in the 6-0 win against Slovakia on Jan. 12.
Thomas Tuchel says it was imperative that his side started the second half of the Bundesliga season with a win.