Montee Ball was Mr. Durability at the University of Wisconsin, missing just one game while scoring an NCAA record 83 touchdowns.
He hasn't had the same endurance in the NFL.
The second-year pro got off to a slow start this season after missing much of training camp following an emergency appendectomy. Now, he's going to miss several weeks with a torn right groin.
Ball was injured Sunday when he accidentally did the splits while going out for a possible check-down pass in Denver's 41-20 win over Arizona. Emmanuel Sanders caught a 20-yard pass on the play.
"I was going to throw a little chip, and I kind of missed, and then I kind of stepped on his cleat and then my other cleat slipped. I did the splits a little bit. Freak accident," Ball said. "I don't know what's going on, if somebody put a hex on me or something. But I'm not sitting here playing the woe-is-me card.
"I'm most definitely going to stick with the program, train, (trust) the training staff, rehab and I'll come back stronger. Bigger, faster, stronger, that's for sure."
Ball stayed down for several minutes and needed help as he gingerly left the field. He was in such pain that Peyton Manning said after the game, "My prayers are with Montee."
There was concern in the organization that Ball had suffered a season-ending avulsion fracture, where the muscle is torn with such force that the ligament or tendon actually rips a chip from the bone. But an MRI on Monday ruled that out.
Ball played in all 19 games as a rookie last season, when he was a backup to Knowshon Moreno, and his 6.5-yard average over the final six weeks of the regular season helped convince the Broncos to let Moreno leave to Miami in free agency.
But three days before the first preseason game, Ball needed an appendectomy and although he was back in plenty of time for the opener, he hasn't been the same runner he was last year.
Ball is averaging 3.1 yards a carry, a significant drop-off from the 4.7 he averaged as a rookie.
It's not all his fault.
Behind a reconfigured offensive line and with a bevy of backs who came into the season with zero NFL starts on their resumes, the Broncos (3-1) have had two dozen carries this season that went for no gain or negative yardage, an alarming one-fourth of their runs.
Defenders have consistently found the gaps between center Manny Ramirez and guards Orlando Franklin and Louis Vasquez.
Vasquez, an All-Pro last year, has been dealing with back and ribcage injuries but hasn't missed any time, and Franklin is transitioning from right tackle to left guard.
By the time Ball got hurt Sunday, the Broncos' ball-carriers had been hit behind the line of scrimmage on 30 of their 70 carries, including on five of seven first-half carries, which resulted in a measly 4 yards.
That number improved in the second half, when the Broncos, behind a resurgent Ronnie Hillman, rushed for 90 yards on 19 carries, minus two kneel-downs. The backs were hit in the backfield on just four of those 19 runs.
"I thought Ronnie came in and gave us a burst and there were better holes in there when Ronnie came in for whatever reason," Manning said.
Well, a big reason was defensive end Calais Campbell had been knocked out of the game by tight end Julius Thomas' chop block, which drew the ire of Cardinals coach Bruce Arians. But Hillman also hits the hole faster than Ball.
"I thought the running game improved throughout the game," Manning said. "(Hillman) averaged something like 5 yards per carry. So we'll continue to work it to be balanced because it's still an easier way to play football and it puts more pressure on a defense."
Juwan Thompson chipped in three carries for 15 yards, including an 8-yard run up the middle for his first career TD. C.J. Anderson was inactive for the game.
"They did a lot of great things yesterday," Ball said of his backups. "They showed they're capable of stepping up and taking the reps when needed. And I told them, all of them on Day 1, I said, 'We're going to need every single one of you guys.' And that's proven."
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