By FOX SPORTS Staff
Schweinsteiger has established himself as an integral part of the Bayern setup ever since he broke into the first team in 2002, with the 28-year-old leading his side to five Bundesliga titles so far in his career with the Bavarian giants.
However, Thon, who played for Die Roten from 1988 to 1994, criticised the German international for failing to live up to expectations this season and claims the one-club man can no longer perform at the top of his game.
"Schweinsteiger is a player who will only further decline simply because he no longer has the speed from before," Thon told Sky 90.
"You need speed and aggressiveness in his position, although I have to admit that Schweini is doing a good job.
"He is showing other qualities and could perhaps stay at this level until the 2014 World Cup.
"After that, he will probably follow the same path as Michael Ballack with the national team.
"It could even [be] sooner. Schweini's mainly playing simple vertical passes and cannot beat his man anymore.
"Borussia Dortmund's [Ilkay] Gundogan brings more to the table at the moment."
Schweinsteiger will nonetheless likely feature for Bayern when they take on Wolfsburg in their next Bundesliga fixture.