In the shadows of the uncertainty that is the current Eagles quarterback situation, what with Sam Bradford a sideline spectator at Tuesday's training session and Mark Sanchez getting the lead reps is Thad Lewis, a player you probably never thought you'd have a chance to meet this season.

Lewis, he of the 21 NFL transactions (look 'em up, they are remarkable) and five teams, is the Eagles' third-string quarterback. He was signed to the Philadelphia roster on September 21 and has been invisible.

Until now.

With Bradford a big, giant question mark after suffering a concussion and a left shoulder injury -- to what degree, we don't know officially -- on Sunday in the loss to Miami, Lewis bumps up the depth chart, temporarily or not. On Tuesday, he shed the role of scout-team quarterback and took second-team reps behind Sanchez as the Eagles prepare for Tampa Bay on Sunday.

It was welcomed work by Lewis, who has thrown exactly 189 passes in the parts of six NFL seasons he's played, 157 of them in a six-game stint with five starts in Buffalo during the 2013 season. That was the best stretch of Lewis' career, and it started in a great way: Lewis started his first game in October at home against Cincinnati and he scored on a 3-yard quarterback draw on his opening drive and then leaped into the stands to celebrate.

The Bills lost that game and Lewis was gone after that lone season in Buffalo and after a late-2014 season role as a backup in Houston and a 2015 Training Camp participant in Cleveland, Lewis became an Eagle. He is the very definition of a journeyman in the NFL, and that's not a criticism. It's a tough league to make, and it's an even harder league in which to stay. 

Lewis started one game in two seasons in Cleveland, when Eagles offensive coordinator Pat Shurmur was the head coach in 2012, and he completed 22-of-32 passes for 204 yards in a season-ending loss to Pittsburgh, decent numbers and a decent performance. But there was an interception thrown to safety Troy Polamalu in Steelers territory. There were some fumbles by rookie wide receivers. There was a crushing blow from linebacker Lawrence Timmons that KO'd Lewis from the game.

It was Lewis' last game in Cleveland. Shurmur's, too. The Traveling Man packed up and moved on to Buffalo in search of a more permanent situation. Didn't happen then. May not ever happen. That's the way life is on the fringe of an NFL roster.

"Obviously a lot of things factor into that," said Lewis when asked about the difference between a quarterback who is a starter and on stable ground in the NFL and a quarterback trying to reach that level. "Being in a system for the same amount of time, being around the same guys obviously helps because of the continuity you have with those guys. Just getting rolling and working to your strengths and correcting your weaknesses and trying to be the best you can be every week. It's a grind. It's a grind. If you think you know it all, you never know it all, so you've got to approach it and watch film and watch film and watch film and watch film and make sure you perfect your craft out there on the field."

That's hard to do when you're running scout team, which means you're running plays the opposing offense runs and preparing your defense for those looks. It means throwing into coverage and interceptions. It means learning pieces of a new scheme every week. It means preparing the defense, not honing your skills.

But if you want to stay on a roster, you do what you need to do to stick.

"You get better by taking mental reps day after day and then taking your own reps on your time," Lewis said. "I know there is only so much time on the field for our quarterbacks and only so many reps to go around."

Bradford's injury, suffered in the second half of Sunday's loss, comes at a particularly crucial time with games on Sunday against Tampa Bay and then four days later on Thanksgiving at Detroit. Lewis may not even factor into the picture, but on this day at the NovaCare Complex he was a story, and an interesting one for a team desperate for a victory in the short term and a quarterback answer in the long term.

Lewis has bounced around enough to know that he is, as every player knows, "one play away. You always have to have the mentality of 'next man up.' You always have to be ready. I know the playbook and I know that if I'm called on, I will be ready."

Sanchez is the next man up, should Bradford not play against a tough, fast and aggressive Tampa Bay team. And if Bradford isn't dressed, Lewis would be active and in uniform for the first time since the last game of the 2013 season, his swan song in Buffalo.

"I've been here since Week 2, nose down in the playbook since I got here and have had plenty of opportunities to study, so now it's pretty much second nature. I feel very comfortable," said Lewis. "It's similar to what I've done in the past, just different terminology, but the same concepts."

Lewis improved exponentially on Tuesday just by taking some practice reps. If all goes well, we won't see him ever take a snap in a game this season. But you never know. The "next man up" is Sanchez if Bradford can't play on Sunday and then after that it's a quarterback you never thought would enter the equation in 2015. Welcome to the NFL, where anything can happen. For Lewis, anything and everything does happen.