Since midseason, the Marlins also have traded shortstop Hanley Ramirez to the Dodgers, right-hander Anibal Sanchez and infielder Omar Infante to the Tigers and closer Heath Bell to the D-backs. Reyes, Buehrle and Bell were signed as free agents last winter.
The Commissioner said he can see the situation from both perspectives.
"I am aware of the anger [among some Marlins fans]," Selig said. "I'm also aware that in Toronto, they're very happy. But I'm sensitive to [the reaction in Miami]. We're doing great, but I have a great sensitivity to fans and people in areas. Remember, my career started because the Milwaukee Braves went to Atlanta and I never forgot the hurt that I felt and everybody around. So I'm not insensitive to that. I've lived through it.
Selig said he's talked to baseball people who believe the Marlins "in terms of young players, did very well."
"These are two independent baseball people," Selig said. "So I want to think about it and I want to review it. I want to be my usual painstaking, cautious, slow, conservative self in analyzing it.
"In a trade where it's just for cash, that's a different story. That's easy. Other than that, clubs have to make their own decisions. And that's not up to the Commissioner, by the way. But I will talk to a lot of baseball people. We'll talk about all those things. The questions are fair about the Marlins' fans."
Selig was asked how the Blue Jays-Marlins trade differs from the August deal in which the Red Sox sent Adrian Gonzalez, Josh Beckett and Carl Crawford to the Dodgers, lowering their payroll in the process. He said that deal was reviewed and that it was a "fair analogy."
Selig said he was confident the matter would be resolved.
"You have to start with this context: The sport has never done better," he said. "It's never been more popular, revenues are up, everything is up. But, you know, in life you go through cycles."
"As I said to the owners, and I will tell you this: My job from the day I walked into this office and even the many years that I watched other Commissioners, is to do what's in the best interests of baseball. People have different views of that, of what you should do and how you should do it. But I think I've been able to come through all these situations and the sport's been stronger and better as a result.
"I know what the Commissioner can do, can't do, what his legal responsibilities are, and pick up on this now. I understand all that, and in the end I'll do what I've done in the other past situations. People always as ask me, 'Boy, don't you wish this didn't happen?' Well, there are a lot of situations I wish didn't happen. But they have and I have to try to do what I have to do."