Even Sandberg admitted, however, that playing in Chicago created an environment that allowed him to flourish, a set of circumstances that might not have existed had he stayed with the Phillies.
There is, for example, the fact that he played for Jim Frey in 1984. He called that the turning point of his career.
"(Frey) asked me to do something no coach or manager had asked me to do, which was hit for power," Sandberg said.
After batting .261 with eight homers and 48 RBI in 1983, Sandberg put together a .314-19-84 year, scored 114 runs, and won the NL Most Valuable Player Award.
Then there's the fact that Sandberg played his home games at Wrigley Field.
"From the moment I got to the ballpark, I knew all the games were going to be on WGN and that all my family and friends had a chance to be watching," he said.
"As for Wrigley Field, I don't think there's a better atmosphere," he said. "I enjoyed day baseball and always saw the ball very well there. Anytime I was struggling, I always knew that I had a homestand coming up and everything would be fine."
Finally, there's the fact that he got an immediate chance to play regularly with the Cubs, an opportunity that almost certainly wouldn't have existed had he stayed with the Phillies.
"They were stacked at the positions I played," he recalled.
The Phillies, at the time, weren't even sure what position Sandberg should play. But they had Mike Schmidt at third, Manny Trillo at second and Garry Maddox in center.
"I didn't have many backers in the Phillies' system, either," he said in his 1995 autobiography, "Second to Home."
So maybe he would have ended up in the Hall of Fame anyway if he had remained with the Phillies.
And maybe he wouldn't have.