Van Gaal, whose own position is shaky five months into the job after a disastrous run of form by the German giants, has chucked Toni out for Wednesday's make-or-break Champions League clash with Maccabi Haifa, Bild said.
There is little love lost between the Dutchman and his Italian star. Signed from Fiorentina in 2007, Toni was the Bundesliga's top scorer in his first season, scoring 24 times in 31 league games on the way to Bayern winning the German title.
But after struggling with injury last season, Toni has seen Germany's stars Mario Gomez and Miroslav Klose, plus promising youngster Thomas Müller dominate the forward positions.
Having made just four league appearances this season since van Gaal took over on July 1, the 32-year-old Toni has become increasingly frustrated.
Toni stormed out of Bayern's 1-1 draw with Schalke 04 in the Bundesliga on November 7 after the coach replaced him at half-time and the Italian was later fined for his conduct and apologised.
He was left out of the match day squad for Bayern's 1-1 draw with league-leaders Leverkusen last Sunday.
It looks increasingly likely Toni will be sold during the Bundesliga's winter break in January and the Italian has already dropped hints saying he has a good relationship with Roma captain Francesco Totti.
On Tuesday Toni let it all come out.
"For four months, I have had a problem with van Gaal," Toni told Italian television station RAI 3. "Everything has borders and our relationship is nearly at the end. I would like to return to Italy so I can start scoring goals again and get back into the national team."
Munich's chronic lack of top form under van Gaal has left them seventh in the Bundesliga.
If Bayern suffer an embarrassing home defeat to Haifa, their Champions League campaign would be dead and buried - and possibly van Gaal's job with it.