"But we've got a whole bunch who don't really understand what it really takes to play at this level. They're going to be challenged for the next 13 days, considerably, every day if we're going to get better."
Fulmer said he expects those younger players to impress the coaching staff, not wait around to be asked to take certain challenges.
"We're going to have some miserable guys. They say you comfort the afflicted and afflict the comfortable. We've got too guys who are many comfortable right now with where they are. They're just trying to go through the motions of being a college football player rather than get down to trying to be the kind of man who contributes to the team.
"We're going to sort those guys out. If it takes the same five offensive linemen and the same four defensive linemen playing the entire game, that's what we'll do."
The Vols spent 2 1/2 hours on the practice field Saturday for the second straight afternoon, capping the first of five weeks of spring practice. Fulmer said it's the fundamentals that mean the most right now.
"There are three things we can control - our attitude, our effort and our toughness," Fulmer said. "Every man can control that. It comes down to getting in front of the whole team and stepping up. We've got some guys who do and some guys who don't yet understand how."
Tennessee practices again Tuesday and Thursday, with Saturday likely the first spring scrimmage date. The EdAmerica Orange and White Game takes place March 31.