When Antonio Smith walked off the field after Super Bowl 50, he believed it was his last NFL game. The 34-year-old defensive end finally won the championship ring he had strived for his entire career.
Smith, who came close in 2008 when the Arizona Cardinals lost to the Pittsburgh Steelers in Super Bowl XLII, played for four different NFL teams and even in the now-defunct European league for the Hamburg Sea Devils (2005) in his quest for a championship. 
After 12 years in the league, Smith was finally done.
Until he wasn't.
Smith soon realized, it wasn't enough. He still missed the game of football.
"As time went by, you start seeing guys go back to practice, you talk to your friends, you start seeing the games you know. It's always still there, but I knew then I wasn't done. I thought I was but I wasn't."
More than seven months later, Smith would get another chance to play. When he received the call from his agent that the Texans wanted him to come by for a workout, Smith didn't ask why. The 34-year-old was happy to return defensive end found out Tuesday night it was because three-time Defensive Player of the Year J.J. Watt was headed to injured reserve.
Smith, who left Houston in free agency after the 2013 season, knew Watt from his days as a rookie. He saw Watt return his first career interception for a touchdown in the Texans first playoff game in franchise history. In 2012, he played alongside Watt when he received his first Pro Bowl nod, All-Pro honors, and was named AP Defensive Player of the Year.
Smith knows from being Watt's teammate and watching from afar, there's no replacing him.
"I'm definitely not a replacement," Smith said. "Man, I love that kid. I don't even think he knows how much I love him. But, no replacement at all, I'm just here to help the team out as best I can. That's how I've always seen the game, how I've always seen my role, my responsibility whether that's a bigger role or a smaller role. I just have to come in and do the best I can."
Now as a Texan (again), Smith will have his challenges. First, he needs to get back into football shape after missing the grind of training camp and not playing in a game since the Super Bowl win with the Denver Broncos. The second challenge will be learning the playbook and becoming familiar with the terminology used by a new coaching staff.
But, he still has juice left from what head coach Bill O'Brien has seen.
"Obviously, he hasn't played football in a while, no question about it," O'Brien said. "We're going to work hard to work with him to help him get back into football conditioning. But that'll be a big part of how much he plays and things like that."
Smith agrees. He hopes to get up to speed "by any means necessary" so that he can contribute. It's part of why he wanted to return to football. 
"I still love the game, I still love to compete, I still can rush the passer so there came a point where I missed it too much," Smith said.
The player, formerly known as the Ninja Assassin, put his costume away for a few years. Who knows if it comes back now or ever? For now, Smith is just happy to back in Houston.
"It is very special to me. This is home. 
Smith started 78-of-79 games during his five seasons in Houston (2009-2013) and registered 194 tackles, 27.0 sacks, seven forced fumbles, and three fumble recoveries.

When Antonio Smith walked off the field after Super Bowl 50, he believed it was his last NFL game. The 34-year-old defensive end finally won the championship ring he had strived for his entire career.
 
Smith, who came close in 2008 when the Arizona Cardinals lost to the Pittsburgh Steelers in Super Bowl XLII, played for four different NFL teams and even in the now-defunct European league for the Hamburg Sea Devils (2005) in his quest for a championship. 
 
After 12 years in the league, Smith was finally done.
 
Until he wasn't.
 

Smith soon realized he had more football left in him. He still missed the game.
 
"As time went by, you start seeing guys go back to practice, you talk to your friends, you start seeing the games," Smith said. "It's always still there, but I knew then I wasn't done. I thought I was but I wasn't."
 
More than seven months later, Smith would get another chance to play. When he received the call from his agent that the Texans wanted him to come by for a workout, Smith didn't ask why. The veteran defensive lineman was happy to return to his former team for another opportunity. Later Tuesday night, he discovered it was because J.J. Watt, the three-time Associated Press Defensive Player of the Year, was headed to injured reserve.

"I know Antonio has a good reputation, he comes well recommended and he has good veteran experience," defensive coordinator Romeo Crennel said. "So, we feel like that experience will be able to help us, losing someone like J.J., so you bring a veteran in who knows how to play the game, who gives you some inside pass rush. That's what we're looking for from him."

Smith, who left Houston in free agency after the 2013 season, watched Watt develop first-hand from his days as a rookie to the NFL superstar he became. He saw Watt return the iconic interception for a touchdown in the Texans first playoff game in franchise history. In 2012, Smith played alongside Watt during the season when the second-year defensive end received his first Pro Bowl nod, All-Pro honors, and was named AP Defensive Player of the Year for the first time.
 
Smith knows from being Watt's teammate for three seasons and watching from afar for the last three, there's no replacing him.
 
"I'm definitely not a replacement," Smith said Wednesday. "Man, I love that kid. I don't even think he knows how much I love him. But, no replacement at all, I'm just here to help the team out as best I can. That's how I've always seen the game, how I've always seen my role, my responsibility, whether that's a bigger role or a smaller role. I just have to come in and do the best I can."
 
Now as a Texan (again), Smith will have his challenges. First, he needs to get back into football shape after missing the grind of training camp and not playing in a game since the Super Bowl win with the Denver Broncos. The second challenge will be learning the playbook and becoming familiar with the terminology used by a new coaching staff.
 
But, he still has juice left from what head coach Bill O'Brien has seen.
 

"Obviously, he hasn't played football in a while, no question about it," O'Brien said. "We're going to work hard to work with him to help him get back into football conditioning. But that'll be a big part of how much he plays and things like that."
 
Smith agrees. He hopes to get up to speed "by any means necessary" so that he can contribute. It's part of why he wanted to return to football. 
 
"I still love the game, I still love to compete, I still can rush the passer so there came a point where I missed it too much," Smith said.
 
The player, formerly known as the Ninja Assassin, put his costume away for a few years. Who knows if it comes back now or ever? For now, Smith is just happy to back in Houston.
 
"It is very special to me," Smith said. "This is home." 
 
Smith started 78-of-79 games during his five seasons in Houston (2009-2013) in which he registered 194 tackles, 27.0 sacks, seven forced fumbles, and three fumble recoveries.