The Swansea's midfielder, who has played an integral part in the club's rise through the four divisions, has been tipped for an England cap.
"He's a terrific player," Toshack told the Daily Mail. "But I wonder if, at the age of 30, international football has passed him by. I think as a team Swansea operate better than their individual talents suggest.
"That includes Wayne Routledge, who has found it difficult to settle at a number of clubs but is playing his best football at Swansea."