The Republic of Ireland Under-19 international captained Villa's Under-21s for most of last season.
Cowans, who made 527 appearances for Villa in three spells between 1976 and 1994, was speaking to AVTV after his side finished the Under-21 Premier League season in seventh place in Division 2, having recorded eight wins, three draws and 11 defeats.
Despite an up-and-down term, the club legend was pleased with much of his squad’s progress and picked out Toner as the star performer after he started all but the penultimate game of the season.
The promising defender, 18, also captained the side from mid-September onwards and trained with the first-team on several occasions following Tim Sherwood’s appointment as Villa manager.
Set to be out of contract this summer, the likes of Leicester, Newcastle, Norwich and Stoke are reported to have been monitoring his situation, but the claret and blues are believed to have made an offer of fresh terms [h/t Daily Mail].
Speaking on his star of the season, Cowans said: “Probably Kevin Toner. He gets his head onto everything. He’s a throwback to the old days. He just heads it, kicks it, clears it and he’s comfortable on the ball.
“He’s got a bit about him.”
In addition, Cowans reserved special praise for forward Andre Green, who made the first-team bench for the Premier League finale against Burnley alongside fellow front man Callum Robinson.
Having just turned 17 last month, the promising speedster stepped up from the Under-18s to make eight appearances for Cowans’ side last term and the Villa coach believes that a bright future awaits.
He added: “Andre is a young old lad who is very talented. He’s got a hell of a chance.”