The rain poured on and off during the second Falcons training-camp practice.

But Ricardo Allen didn’t care.

It wasn’t enough rain to force practice inside, but it was enough to make anyone uncomfortable. At times it simply drizzled, and at times the rain fell consistently. There were ups and downs, something that resembles Allen’s career.

For the first time in months, Allen lined up with the starting defense for 11-on-11 drills. Allen energetically clapped his hands and communicated with the secondary from his free safety spot before the first snap.

After a few short plays, he jogged to the sideline and cheered on younger players. Coaches want to tread lightly with Allen, who’s returning after missing nearly all of the 2018 season with a torn Achilles. If he had it his way, he’d have played every down.

As the Falcons lean on his leadership, which they missed so dearly, he’s adapted physically and mentally. And now, he’s ready to unleash a year of bottled-up lessons to everyone who’s doubted him since he entered the NFL.

‘A game of chess’

In overtime against the New Orleans Saints in Week 3, Allen diagnosed a run toward his opposite side. He progressed as he normally would, backpedaling to find a pursuit angle. But suddenly, he felt a sharp pain near his left ankle. He thought a receiver or a teammate collided with him as they scrapped for position. But when he turned and saw no one around, he realized what happened.

Allen knew what the coming journey entailed. The looming rehabilitation didn’t upset him, though. The way he injured himself frustrated him more, he said.

“It’s funky because I’m a fighter,” Allen said. “I play hard, and for me to go out that way, it was kind of soft. But sometimes it’s out of your control and you have to take it for what it is.”

The Falcons lost the game. But more important, they lost the voice and glue of their defense.

And he wasn’t the only one. Allen’s injury marked the third defensive starter to go down to that point. His counterpart, strong safety Keanu Neal, tore his ACL in the opening game. Linebacker Deion Jones injured his foot in the same game.

Allen’s injury sealed the Falcons into months of shuffling around defensive starters, relying on young players in a competitive division.

The Falcons placed Allen on injured reserve, and he underwent surgery. He watched the Falcons limp through a 7-9 record, while he dealt with a new obstacle.

Allen knows how to intercept passes and be a solid defender — in five NFL seasons, he has 229 tackles and seven picks. But in his 13 years of playing football, Allen said he’s never suffered a serious injury.

This challenged him.

“Everything just slowed down,” Allen said. “You really don’t understand how grateful you are to just get up on two feet. When you lose your Achilles and need to use the bathroom, you’re laying in bed, so you have to roll over and get on a cart. It’s just little things like that.

“When you get hurt, it makes you realize how hard it is to get back into this league, and it’s already hard enough to get into this league.”

While he labored to recover his body, he also improved his mind. His teammates and coaches said he’s always been a cerebral player. But during his injury, he elevated.

He filled the extra time by studying offensive schemes. First, he looked at Kyle Shanahan, the Falcons’ former offensive coordinator who propelled the team to lead the NFL in scoring during their 2016 Super Bowl run.

He then studied the late Bill Walsh, a Hall of Fame coach who won three Super Bowls leading the San Francisco 49ers in the 1980s.

Walsh, respected as one of the greatest offensive minds ever, has a coaching tree still intact today, including Mike Tomlin, Jon Gruden and Andy Reid. Within a month, Allen took it further, joining the Falcons quarterbacks in their meeting room to analyze film from their perspective.

“Every side of the ball thinks they have the advantage,” Allen said. “On offense, they’re playing on matchups and what weaknesses they think they’ve seen. It was cool to learn actually what the quarterbacks were doing and how they try to move players and attack coverages.

“When you sit down and think about it, it’s more like a game of chess than it is just banging and running.”

Quarterback Matt Ryan said that is the first time a defensive player asked to study film with him. There wasn’t much teaching from his end, Ryan said. By Allen just watching, he thinks it’ll take his knowledge to another notch.

“I was impressed by him wanting to do that,” Ryan said. “I think he feels like that can add to him being a better player. If that’s the case, I feel like that’s awesome. ”

Allen said he’ll apply that knowledge to the whole defense in meetings and on the field. He said he’ll be able to explain why offenses do what they do, and it’ll give him more authority to offer input for alignments and strategies.

He’s still working gingerly into the rotation, but said if coaches don’t monitor his snap counts, he wants to go full speed. This season is a chance to further cement that he belongs.

“I’m at the end of my recovery, so it was cool to prove to myself that I am who I thought I was.” Allen said. “When times are good and when times are bad, I’m still the same person. I just put my head down to grind.”

A story worth repeating 

By now, the story is ingrained in Falcon lore, but it’s a story Allen loves sharing.

On the last day of his rookie training camp in 2014, Allen, a fifth-round draft pick from Purdue, sat in front of general manager Thomas Dimitroff and then-coach Mike Smith. On national TV, thanks to the cameras of the HBO series “Hard Knocks,” the Falcons released Allen, but relegated him to their practice squad. Since then, he’s climbed to a starting role and signed a three-year, $19.5 million contract extension last season.

Allen said that early pitfall demonstrates that anyone can be successful. His coaches agree.

“It's a testament to who he is and how hard he works,” secondary coach Jerome Henderson said. “He tells young guys all the time that, ‘Look, when I came in, I was last on the depth chart, and I ended up getting cut. But that didn't take away my passion to want to contribute to this team. And everyone in this room needs to find that.’”

Defensive end Vic Beasley said having Allen back will impact the whole defense, not just the secondary. Even in the trenches, Beasley said he missed having Allen behind him, and he’s excited to have him healthy.

“He’s very special, and he’s worthy to be here,” Beasley said. “For a guy as smart as him, he definitely brings a lot to this team, and we can’t take it for granted.”

Coach Dan Quinn said the staff will monitor Allen’s health and adjust his practice slate. But in a division where the Falcons play elite quarterbacks such as Drew Brees and Cam Newton, the Falcons will need him ready.

He’s excited to get back, because he knows he’s prepared. And, like his entire up-and-down career, he said he’ll maximize his opportunities when they come.

“I've been told plenty of times that I’m not good or I will never play,” Allen said. “I don't take it personal. It is what it is. I’m a warrior, and I’m just happy to be back on this field.”