Ricardo Clark plays the part of invincible man well. 

The midfielder with seemingly endless energy represents the standard for what a box-to-box MLS midfielder should be. At 32 years old, he’s even found an attacking touch late in his career, with an MLS-career-high five goals in 2015 with eight games left to go.

It's a remarkable development, especially since two years ago Clark wasn’t even sure if he’d ever play again.

The ironman was sidelined back in 2013 by a heart arrhythmia that emerged during an Aug. 17 home game against Seattle. When he exited the match in the 39th minute, it would take 22 days before he returned to an MLS match. And for the first time, the man that never slowed down on the field was forced to evaluate the state of his career.

“It was a very scary moment,” Clark told MLSsoccer.com. “You hear [the] extreme scenario of people passing out on the field and you don’t want that to happen to you, obviously. It was almost like you have no control of the situation.

“Yeah, I definitely looked at that possibility [of retiring],” Clark continued. “I wanted to prepare myself for any scenario. It was a scary moment because I was contemplating whether I wanted to continue on with my career.”

Clark immersed himself in information about his condition. What he learned was not immediately comforting.

“I pretty much researched the whole topic. I went online and researched it and you can find some pretty horrific things online, but those are extreme cases,” Clark said. “Thankfully, mine was somewhat of a mild case, but I wanted to make sure everything was straight before I stepped back on the field.”

The Houston Dynamo did just that. The club immediately examined Clark at the stadium on that August day in 2013 and then had him undergo a battery of tests over the days and weeks that followed: EKGs, an echocardiograph, a heart monitor and a 12-lead stress test. The results ruled out any abnormalities. 

"None of these things came back with any significant issues that were noted,” Dynamo head athletic trainer and director of sports medicine Theron Enns told MLSsoccer.com. "Bones and muscles heal, but you have only one brain, you only have one heart.

"Part of our job is to explain to the player what’s going on, but also to explain to them why things are OK and that they will be fine once they return and give them the confidence and all the backup they need to put them back on the field."

Even with those reassurances, the veteran midfielder still went out of his way to find new ways to get his body right.

“I picked up more of my yoga, which includes a lot of breathing and stretching, which opens up channels of breathing in the body,” Clark said. “I feel the more I was dedicated to that, the less I would feel the episodes come on.”

He would eventually return to start seven more matches to close out the 2013 season, only to return the following season and have to deal with a concussion which kept him out of nine matches. But those incidents are now a thing of the past and Clark started 39 straight MLS matches before a right hamstring injury interrupted the streak earlier this month. He's back in training and could see time on Saturday night against the Vancouver Whitecaps (8 p.m. CT, TICKETS).

“Every player has something that makes them tick and that’s what makes me go, doing that extra work and paying attention to details in my game,” Clark said. “Maybe I’m a little OCD or ADD, but at the end of the day I enjoy when I’m doing that and it’s a combination of things that keeps me going.”

Said teammate and forward Will Bruin: “In the dead of summer he’s out there doing extra [work]. He’s out there having fun with it. It’s awesome to see, it’s a great example for the young guys and he’s a great leader. What he’s been doing on the field this year so far is showing all the hard work he’s put in.”

All the work is indeed paying off, as Clark is having his best year in the attacking half. New Houston manager Owen Coyle has asked him to change his focus from destroyer to box-to-box midfielder and that move up the pitch has seen Clark put his endless energy to good use on both sides of the ball.

In addition to the career high in goals (five), Clark is tied for second on the team in shots on goal thus far this year with 16, just one behind top goal scorer Will Bruin. 

“Obviously it’s exciting to get forward. A lot of players are envious of forwards because they get to do the fun stuff in the games,” Clark said. “It’s funny how that’s working. I’m just thankful for the opportunity to be playing and be healthy. Knock on wood, I want to keep striving and keep improving.”

Darrell Lovell covers the Houston Dynamo for MLSsoccer.com.