For stretches during the 2011 season, that upside was clear. The pair combined for 64 tackles and six tackles for loss and played an instrumental role as the Wildcat defense turned in its best two efforts of the season, allowing just 593 total yards against Georgia and Tennessee.
With some meaningful experience behind them, Cobble, Rumph and the defensive line at large are no longer the future. They are the here and now.
"The defensive line should be the strength of our defense, should be the strength of our football team," head coach Joker Phillips said.
Juniors Cobble and Rumph are joined along the front line by projected starters at end Collins Ukwu and Taylor Wyndham and a promising stable of reserves, most of whom are sophomores and freshmen. With plenty of talent, experience and size, Phillips is asking for the line to set the tone for everything the Wildcats do this season.
"Everything on our defense starts up front," defensive line coach David Turner said. "That's the group that's got the most experience and that's the group that's going to be able to handle it."
With stalwarts like Danny Trevathan, Winston Guy and Ronnie Sneed gone from the linebacking unit and secondary and off to NFL training camps, UK is much shorter on experience farther from the line of scrimmage.
"Somebody's got to do it and why not us?" Turner said. "That's what I tell the guys. Why not us? For us to be any good on defense, we've got to be better up front. That's plain and simple. I tell the guys we don't worry about who we play, we don't worry about when we play or where we play. We got to handle us. It starts with us. Don't worry about anything else but us getting better. If we do that, we'll be a better football team."
Cobble and Rumph, in particular, have heard about how they are supposed to transform the UK defense throughout their careers. Because of that, they are having no trouble taking their coach's cue.
"I don't really like to look at things like that, to try to speculate what may happen," Cobble said. "I just like to just look at it now, take it day by day. As of now, me and Donte's main focus for this camp is just to get the team better. To get the defense better, to get the offensive line better."
Due to academics, Cobble had to wait a long time before finally suiting up for UK. He spent most of his first two years on campus working to improve in the classroom, learning the system and trying to become better conditioned. With all that on his plate, serving as a leader was the last thing on the mind of the 6-foot, 328 pounder. Now that he's settled in on the field and in the classroom - his grade-point average is up to 2.6 - he's also coming into his own as an example for his teammates.
"It's been a slow learning process for me," Cobble said. "Coming into college, I had my ups and downs but as time went on I started to just learn and take time to adapt. It all just came to me one day and I feel like I have a better understanding of what's going on around me. I feel more inclined to do more things."
In spite of their size, Cobble and Rumph have always been soft spoken, which means they are more comfortable leading by doing.
"To show how to walk the path, you must walk the path yourself," Cobble said. "So yes, doing things right all the time will be a main thing but, at the same time, you also have to teach the people how to do it. And by doing it, like I said earlier, they have to see you doing it."
However, Ukwu - who is a strong vocal presence on the team - hears the two talking more and more.
"PC and Donte's personality both, they're not really vocal guys," Ukwu said. "I feel like this summer especially, you hear them trying to encourage people get them to turn things up. That's something that's great. It's less talking for me. That's what you want. You want everybody on your team to be a leader because that's what makes great defenses and great teams."
The bottom line is that the defensive line now has many different kinds of leadership from various sources, which figures to be an asset through the rigors of fall camp and beyond.
"It's kind of been leadership by committee," Turner said. "The guys know, they understand what we're trying to get done and what we expect and trying to live up to that."
Also helping things is the fact that all of UK's returners have season in defensive coordinator Rick Minter's system under their belts.
"I just feel like just being in this defense, I've learned a lot and it's allowed me to mature because it's just so much to process and as I'm trying to process and learn and understand it and hold all of it within, it's allowed me to do more outside of football as well," Cobble said. "My mind is trained to do that now."
They know their assignments and they know how important those assignments are to the goals of the team at large.
"Basically the (defensive line) really controls what happens between each and every play," Cobble said. "If we mess up even one time, a slight mess up can cause the whole defense to fall. It's like a house, we're at the bottom and if we fail to hold it up (it all falls)."
Serving as the foundation for the entire defense and being asked to be the best unit on the entire team is a lot of pressure, but this group has been waiting a long time for this kind of opportunity.
"We love it," Ukwu said. "It's something that you want, because we know how we work as a defensive unit and a d-line. We feel like we work hard. If people are looking at us, we feel like we should be the focal point of the whole team, that this is how we do things."