"I never saw Joe Jackson, he was a little before my time," Reinsdorf said by phone following Thomas' retirement from baseball. "I started following baseball in 1945 and the only right-handed hitter I've seen since then that I would put in the same class as Frank is [Cardinals' slugger] Albert Pujols. I can't imagine he doesn't get into the Hall of Fame right away."
Despite Thomas' acrimonious departure from the Sox in 2006, he said that Reinsdorf was the first person he called when he decided to announce his retirement.
"And that conversation was as warm as all our conversations have been over the years," Thomas said. "People think we've had a rocky relationship; we haven't."
Reinsdorf said Thomas' news "came up so fast, I just couldn't get in" for Friday's news conference. But he also said the two have always been on good terms.
"I don't ever remember having a cross word with Frank," Reinsdorf said. "It would have been nice if he played his entire career in one place, but that almost never happens anymore. He and I always talked about that.
"We've talked the last several years about him coming back to the organization in some capacity when his career was over. We're going to sit down and talk about it."
As for Thomas' legacy as a slugger never suspected of steroid use, Reinsdorf added, "He should have won a third MVP," referring to 2000, when Thomas was edged out in the balloting by Jason Giambi, who later admitted to using performance-enhancing drugs that season.
Reinsdorf addressed the criticism Thomas favored drawing a walk rather than trying to drive a runner in.
"That's what they used to day about Ted Williams also," he said. "He took a lot of walks but the fact is, if you're swinging at bad pitches, you're not as good a hitter. The thing about Frank that was amazing was that a player that size had the plate discipline he had."
Reinsdorf chuckled at the memory of Thomas first coming to the Sox in 1990.
"I don't think he hit a home run the first month he was up," Reinsdorf said. "I was laughing, saying, 'I wonder if he'll ever hit one?' But he hit a few."
Included in that total was Thomas' home run the first time he faced the White Sox wearing an Oakland uniform.
"I actually felt good for him," Reinsdorf said. "I felt bad for us, but good for him. I knew he'd hit a home run."
Reinsdorf said he always thought the characterization of Thomas as sullen was unfair.
"There is a little shyness to Frank," he said. "Sometimes that's easily mistaken.
"It was really an honor to have someone of his caliber play for the Sox as long as he did."
Melissa Isaacson is a columnist and reporter for ESPNChicago.com