Harwell died Tuesday at the age of 92 after battling cancer for the last nine months.
"He was one of the neatest, classiest, talented guys in this game," La Russa said. "He's one of the neatest men I've met in all of the 40-some years I've been in baseball. He was the real deal. Great man."
Harwell called Tigers games for 42 of his 55 illustrious years in Major League Baseball. He started with the Tigers in 1960.
"I had great respect for him," La Russa said. "He really knew how to do that job."