Allen is projected by many to be the leading pass catcher this fall and Diehl is regarded as the most punishing blocker on the team.
"Chad and Dwayne had solid springs for us. They did a nice job, but they also probably should have," Pearman said. "It's their time to perform. They've been around here. They both need to step up, not only in performance roles, but in leadership roles as well."
Pearman gave high praise to Allen when asked who he thought the third-year sophomore reminded him of.
"One kid that has been in (the ACC), that did a nice job, maybe a Vernon Davis…I think (Allen) is pretty similar athletically to him," Pearman said.
Running backs coach Andre Powell provided high praise in his comparison for Diehl, who he referred to as a freak.
"There's not a guy in this league, that plays his position, that can do what he does, day in and day out," Powell said. "I had Madison Hedgecock, who won a Super Bowl for the (New York) Giants and played with the (St. Louis) Rams before that. He didn't do what Chad does. When Chad hits people, he hurts them."
Clemson should experience little, if any, drop-off with Dwayne Allen taking over for former Clemson tight end and now Atlanta Falcon Michael Palmer. (Roy Philpott)
"I've been very pleased with (Allen's) progress (mentally). Learning coverages, learning defenses, how to get open—where are you in the progression of the read? Things that help you—understanding the depths and spacing of routes—things that he hasn't taken very seriously, up until the last little bit," Pearman said.
Powell said Diehl has come a long way with his ball skills since he first stepped on campus.
"We'll throw him a pass now. It was before, when he first got here, he could catch a beach ball. He works every day after practice in improving his ball skills and it's paying off for him," Powell said.
Beyond Allen and Diehl, there's plenty of work left to be done at the position.
"We've moved Darrell over about mid-spring. He's got an awful lot to learn to try to help us," Pearman said. "We've got Drew Traylor and Kasey Nobles, as well. They got quite a bit of work in the spring. I was encouraged by the end of spring. They could work themselves this summer, hopefully to help us."
Freshmen Sam Cooper and Victor Beasley will be arriving later this summer with other members of the 2010 class.
"They've got some work ahead of them, once they get on campus," Pearman said. "They'll be joining, hopefully both of them second session summer school."
During his recruitment, Beasley was also being considered as an outside linebacker. Pearman has no worries about losing Beasley to the defensive side of the ball this year.
"We're going to do what's best for our football team. If he can play, wherever he can help us the fastest, I think that's what you've got to do," Pearman said. "I can have all the players and be unemployed. We've got to do what's best for our football team. That's where we'll start him, at tight end."