MANKATO, Minn. -- Though Minnesota Vikings coach Mike Zimmer maintains the team will have an open competition at quarterback during training camp, he does have an incumbent in his mind for now.

Zimmer said veteran Matt Cassel -- who started the final four games of the 2013 season -- heads into camp as the No. 1 quarterback. Cassel and Teddy Bridgewater got more snaps than Christian Ponder during the Vikings' organized team activities and minicamp, and while Zimmer said all three quarterbacks will get similar work at the beginning of camp, the Vikings will eventually start tailoring the practice work toward specific quarterbacks.

"It’s not exactly even -- one-third, one-third, one-third," Zimmer said. "It’s a little bit more and then some drills it’s going to be a little bit less. You’ll figure it out by watching practice."

Cassel, who signed a new two-year, $10 million contract after opting out of his original deal in February, starts camp with the benefit of the doubt, but Zimmer said again the Vikings wouldn't be afraid to start Bridgewater as a rookie if he's ready.

"They’re going to determine who the starter is on the practice field about how they go about their business, how they perform in the preseason games," Zimmer said. "I understand the quarterback’s a big situation. Part of the question about answering who the quarterback’s going to be is, what kind of defense do we have? What are we going to ask the quarterback to do? How can we use the quarterback in different ways. I think a lot of that has a factor on who the quarterback will end up being."