The College Football Playoff expansion debate is heating up again, and SEC Commissioner Greg Sankey is not ready to rush to a decision. As the Big Ten's 24-team field proposal gains momentum among conference leaders, Sankey is urging the sport to slow down and think through the consequences. Speaking on The Paul Finebaum Show from the Regions Tradition Pro-Am in Birmingham, Sankey made clear the SEC has not moved from its preference for a 16-team format . While he stopped short of outright rejecting the 24-team concept, his message was pointed. "We have to do the homework," Sankey said. "And when we went from 4 to 12, I think one of the mistakes was we announced we're going to 12 and then negotiated with the media. We should understand the media marketplace before we have an increase in, for example, the number of teams." SEC vs. Big Ten on playoff format The standoff between Sankey and Big Ten Commissioner Tony Petitti is the central tension in this story.…