He still managed to throw for 4,659 yards and 37 touchdowns for the 13-win Broncos.
Ahead of his second season in Denver, Manning appears to be regaining the arm strength he lost and the nerves in his neck have slowly regenerated. With two tall, vertically effective receivers and a slot weapon like Wes Welker at his disposal, the veteran quarterback should be even more lethal than the handicapped (yet still effective) version we saw in 2012.
According to Andrew Mason of the Broncos' official site, both Eric Decker and Demaryius Thomas think Manning's arm is stronger now than when he arrived in Denver.
“We worked out at Duke in March or April and I definitely felt like he had more zip on the ball," Decker said. "I think he’s come back stronger."
"I think he's gotten a little stronger, but I can't really say, because it's my first time playing with a quarterback like Peyton," Thomas said. "It was fun this past year, because I'd never had balls come at me like that -- on time and stuff like that."
Peyton Manning's arm looks stronger - throwing with plenty of zip #broncos OTAs day1— Cecil Lammey (@cecillammey) May 20, 2013
Manning's added arm strength could make all the difference for the Broncos offense in 2013.
On the outside, Decker and Thomas—who both stand 6'3"—have the opportunity to become even more dangerous vertical threats.
That said, the receiving tandem was more than effective with a still recovering Manning in 2012. In fact, the Broncos were one of the NFL's better vertical passing offenses.
According to Pro Football Focus (subscription required), Manning was first in the NFL in deep passing touchdowns (attempts of 20 yards or deeper) with 11 and second in deep completion percentage, but also second in deep interceptions (six). Several of the turnovers appeared to be a direct result of Manning's arm strength lacking on sideline or seam throws.
Three of the interceptions can be seen in the video below:
Despite a handful of turnovers, Manning's receivers were still highly productive down the field.
Thomas finished as PFF's top deep-passing receiver, having caught 53.3 percent of his targets over 20 yards. His 16 catches on 30 targets for 498 yards and five scores were each in the top three for receivers, and only Dez Bryant joined Thomas as receivers with at least 400 yards, five touchdowns and a catch rate over 50 on deep attempts last season.
Decker caught just eight of 23 deep targets, but added 257 yards and two touchdowns.
Adding Welker to the mix should continue opening up the Broncos' offense vertically.
The most productive slot receiver in NFL history, Welker has hauled in at least 85 catches from the inside in each of the last two seasons (per PFF), and at least 100 total catches in five of the last six.
Welker's mastery of the slot—even if he doesn't break 85 catches from the inside or 100 total—will condense coverages and open up avenues for Manning to attack vertically via Decker and Thomas. Manning's regeneration of arm strength should ensure that he's well prepared to take advantage of those new opportunities down the field.
As fantastic as Manning was throughout 2012 (save for one clunker in Atlanta), the veteran quarterback should have the chance to be even more productive and explosive for the Broncos in 2013.
A stronger arm for Manning and an ideal set of offensive weapons—in terms of both vertical options in Thomas and Decker and underneath with Welker—could very well make the Broncos the most effective passing offense in football next season.