The questions Willis McGahee hears now really aren't so different from the doubts others had about him nine years ago, when he was drafted in the first round despite a significant knee injury suffered in his final college game.
Would he be fast enough? Can he handle the burden of being a No. 1 running back?
"That's always been a question since I came into the league," McGahee said. "You know what? I really don't care what they think. My job is to go out there and prove them wrong, and I'm going to prove them wrong."
Now entering his 10th season in the NFL, and at 30, McGahee gets age questions added to the mix, even after a 2011 season in which he rushed for 1,199 yards, had seven 100-yard games and made the Pro Bowl as an alternate.
But was his success a product of the Broncos' run-heavy, read-option offense under quarterback Tim Tebow?
It's easy to answer yes, because before the quarterback switch in mid-October, the Broncos were rushing for only 101.8 yards per game, 22nd-best in the NFL. By the time the season ended, the Broncos led the league in rushing, averaging 164.5 yards.
But a closer look at McGahee's totals show he stayed remarkably consistent. He had three 100-yard games in four starts playing behind Kyle Orton, and he averaged 20.3 carries per game in those starts. That incarnation of the Broncos' offense featured a more traditional passing game, with wide receivers Brandon Lloyd and Eric Decker as the featured players.
In 10 starts with Tebow, McGahee had four more 100-yard games, and averaged 20 carries in those starts. In many of those games, the passing game was nearly invisible and Tebow the scrambler drew the focus of opposing defenses.
At first, defenses seemed confused by the read option, particularly in its debut at Oakland in early November. That game was McGahee's best as a Bronco, with 163 yards and touchdown runs of 60 and 24 yards. On both, he sprinted away from the Oakland defense.
"They've got the fastest defensive backs in the league," McGahee said. "It just shows how determined I am."
And that brings McGahee back to the present. He has clearly been the No. 1 running back in training camp and has been getting the veteran treatment through the first two weeks of practice. He will take all of the first repetitions but cede other snaps to the younger guys behind him, such as Lance Ball, Jeremiah Johnson and Xavier Omon.
"The goal is to have him be ready on Sundays," said running backs coach Eric Studesville. "We're trying to get a whole lot of work for him early on so we can rest him, and have him at peak condition going into the season."
During the Broncos' public scrimmage Saturday at Sports Authority Field at Mile High, McGahee broke free around the left edge, burst toward the sideline and threw a fierce stiff-arm that propelled cornerback Drayton Florence out of bounds.
McGahee's run helped the first-team offense, led by Peyton Manning, get into the red zone and eventually led to a touchdown pass.
McGahee has said this summer his personal goal is 1,200 yards rushing — one more than his 2011 total. And it's OK with him if you aren't sure if he can't do it. In fact, he prefers it that way.
"With Willis, he's such a competitor. He kind of responds to the challenge of when people say, 'Can he or can't he?' " said Studesville, who first coached McGahee with Buffalo in 2004. "He takes care of himself so well physically, he's a great teammate to be around, and he pushes himself and other people around him. It's fun to see him now, from where I had him early on. It's really fun for me."