According to Nowitzki, the conversation went like this:
"Good luck," Karl said, "you've got LeBron to start."
Dirk's reply: "Oh, sweet."
Nowitzki narrowly missed winning a starting spot in fan balloting for the first time when San Antonio's Tim Duncan made a late surge in the final round of ballot returns to pass the German.
After Bryant bowed out Thursday because of an ankle injury, NBA commissioner David Stern picked Dallas' Jason Kidd to replace him.
But choosing a starter to replace Bryant was Karl's call, just as East coach Stan Van Gundy will select the player -- likely Boston's Rajon Rondo or Atlanta's Joe Johnson -- to start in place of Philadelphia's Allen Iverson, who withdrew Thursday because one of his young children is ill.
Marc Stein is a senior NBA writer for ESPN.com. Tim MacMahon of ESPNDallas.com contributed to this report.