ENGLEWOOD, Colo. --Trevor Siemian is still several weeks away from completing his rehabilitation from a torn anterior cruciate ligament. But any work he gets right now -- even on a limited basis -- helps the seventh-round pick begin to find his footing at his new level.

At this weekend's rookie minicamp, the former Northwestern quarterback was limited to individual and seven-on-seven repetitions. His passes had plenty of zip, so the injury appears to have no impact on his ability to get set and throw with power.

"It's more footwork at this point," Siemian said. "I've been throwing quite a bit, so it's more working from under center and getting back and being dynamic and explosive. I'm just not there quite yet."

But by the start of training camp, he expects to be. That would put him in a position to compete with 2013 seventh-round pick Zac Dysert for work behind starter Peyton Manning and backup Brock Osweiler.

"I'm just going to understand my situation and that's kind of the cards I've been dealt right now," Siemian said. "Wherever I was going to go, I was going to have to compete. I'm looking forward to that. But for me right now … I've got to get my knee back and go from there."

Although Siemian is expected to work in some periods of practice in the next few weeks, his pre-training camp focus will be on rehabilitation and the mental side of learning how to be an NFL quarterback.

"I think at this point it's just grabbing a playbook and understanding it through and through," he said. "I'm obviously limited, so I'm not doing as much run-game stuff. But yeah playbook and understanding reads and progressions I think is, for a quarterback, the number one thing right now."

Siemian must also learn how to operate under center and make calls in the huddle on a regular basis after working in a no-huddle spread attack at Northwestern.

"It's a bit different," Siemian said. "We were spread, no-huddle, but at the same time, you've got to understand basic football principles and concepts and I think Northwestern did a great job preparing me for that. But like you said, it's a different terminology, so it's going to take some time and work for sure. That's where I'm at right now."

But he's exactly where he hoped he would be heading into the draft: in possession of a chance to make an NFL roster. That was no guarantee heading into last weekend, considering that his pre-draft work was limited because of the ACL injury.

"I didn't think about it (the possibility of being drafted) too much," he admitted. "I thought about it a little before my senior year because I figured I'd have a shot to play. But I didn't think about it too much.

"When I got hurt, I just said, 'Shoot, I've got to get my knee back and go from there.' I couldn't do anything without a good knee."

But every day brings him closer to having that issue solved -- and building on what he's already done at rookie camp.

"He's impressive. He can throw it -- just like what we knew we were getting," Head Coach Gary Kubiak said.