The redshirt sophomore, who is listed on Missouri's official website at 200 pounds, said he lost "8 or 9 pounds" about a week ago and had to undergo treatment with the team's trainers. Coach Gary Pinkel said Mauk had a viral infection but that it wasn't too serious.
"Something happened to me, and I lost some weight," Mauk said Wednesday during the third day of SEC media days. "Obviously, it wasn't [anything] bad. I feel fine, I feel great. The main thing is I feel fast. I kind of had speed already, and now I feel like high school again. I'm ready to go out there, and I'm ready to do what I have to do to make our offense as explosive as can be."
Mauk, who went 3-1 as a starter last year while filling in for injured starter James Franklin, said Missouri's trainers ran tests on him, which came back negative. He has since gained back "2 to 3 pounds" of "good weight" but doesn't want to add more before fall practice begins Aug. 4.
"I think I'm fine. I feel great," Mauk said. "Whatever it was, I thank it because I feel great. ... I feel as fast and as light as I've ever been."
Mauk said he believes he got sick because of the extra working out and running he had been doing after recovering from a sore back.
Pinkel said Mauk planned to play with a leaner build this fall in order to be quicker and believes Mauk's weight loss could be a blessing in disguise.
"He might look back on this and say this is one of the good things that happened to him," Pinkel said. "He's always taken care of himself, so that's not a factor."
During Missouri's 2013 SEC East Division title run, Mauk threw for 1,071 yards and 11 touchdowns with two interceptions. He also ran the ball 41 times for 229 yards and a touchdown.