David Sims still thinks about it -- working on the back of a garbage truck.

He is very close to making the Browns as an undrafted free agent. The safety has picked off two passes and impressed the coaches.

"For me, it's about not giving up," said Sims.

And about growing up.

Sims' road to the NFL involved three colleges, one position change and one big mistake.

In 2005, Sims was a star high school running back in Gainesville, Fla. He was told by Florida coach Ron Zook that the Gators might have a football scholarship awaiting him.

"Only Zook was fired, and I had hurt my ACL [knee injury]," he said. "I thought I'd get some scholarship offers, but after I got hurt . . ."

Nothing.

Some junior colleges were interested, but Sims figured he was better than that.

He figured wrong.

So after graduating from high school, he decided to work for a year.

"Waste Management. I was on the garbage truck," he said. "I also worked nights, stocking at Sam's Club."

Working on the garbage truck was a "humbling experience," he said. Sims said he "learned a lot" from that experience.

Like what?

"I had to quit being stubborn and get back to school and football," he said.

Getting cut

When Butte Junior College in California called, Sims listened. He planned to be a running back, but then injured his leg and played little as a freshman.

"The next year, they brought in all these running backs," he said. "I asked them to switch me to defensive back."

He played well enough there to attract the attention of Oklahoma.

"But that didn't work out," he said.

Instead, he landed at Iowa State and was the Big 12 Defensive Newcomer of the Year with five interceptions in 2009. He was named a team captain for 2010, but was later suspended for the team opener -- and stripped of his leadership position.

He was charged with a misdemeanor count of "unauthorized use of a credit card."

While Sims wouldn't discuss the incident, he did say, "I messed up and learned from it."

As a senior at Iowa State he played well, but no one drafted the 5-9, 210-pounder. He was good, but not great. The credit card issue didn't help. And some draft guides said his lack of height was a liability when covering receivers.

A year ago, Sims was in camp with the New York Giants. He survived all the cuts until the last one -- the one that will happen with the Browns on Friday.

"I got cut after the final exhibition game," he said. "They called me in, told me that I played well and I was a 'bright young man.' But they were letting me go."

Sims thought he'd find another team soon.

"I had saved up $5,000 from the money you get in training camp," he said. "I'm glad I did, because after I got cut, no one called. I didn't know how the league worked -- how at this time of year, everyone is cutting their rosters . . . not signing guys."

Still, Sims was determined to find his place in the NFL.

Getting cut . . . again

He was shaken by being dropped at the last moment by the Giants, as well as by a phone call that never came.

Sims talked about how, in the middle of the season, Tampa Bay called.

"I was there for about a week," he said. "Then they cut me when they activated a long snapper."

That's a bit confusing when you are a safety, but Sims was grateful for the NFL regular-season check -- "It was about $14,000." So, he went back home, worked out, and waited for someone else to call.

At the end of November, it finally came. It was the Browns.

"It was a chance to be on the practice squad," he said.

In 2011, practice-squad players were paid about $5,700 a week.

Since Sims was undrafted out of Iowa State, it was a blessing to have a regular paycheck, and a healthy one.

"And I was playing football," he said. "Even on the practice squad, you have a chance to impress some people."

Sims could sense he was close to making it in the NFL. He competed against the Browns' wide receivers and with the other defensive backs in practice. His confidence was growing. No matter what any player says, when no team selects you in the NFL Draft's seven rounds and then when you are cut, twice -- once for a long snapper -- you begin to question your football future.

"But the Browns seemed interested in me," he said. "That's all I needed."

His big chance

There are many players like Sims living on the borders of the NFL, but few of us know their stories.

"I know that I have to do anything to make a team," he said. "I can play special teams. I can get my hands on the ball. I know I can help this team."

Sims is second on the team with 10 tackles this preseason. He leads with two interceptions, one for a touchdown. He picked off a third pass and ran that back for a touchdown, too. But that one was wiped out by a penalty.

"I think he's flashed for the coaches," said coach Pat Shurmur. "He's challenging. He's physical, and he's really made a huge amount of progress in the time that we've been together. . . . He's got to flash, and he's got to make plays. To his credit, he's done that."

Nothing is guaranteed. Sims is being paid the standard $850 a week in expenses. He would qualify for at least the $390,000 league minimum salary if he makes the team.

For most fans, the fourth preseason game is a yawner. For the coaches, it's a game not to play the starters for fear of them being injured before the regular season begins.

For Sims, it's not quite the Super Bowl -- but it's close.

"I know it's an important game for guys like me," he said.

He paused and knocked on a wooden bench.

"I just want to play my game and not get hurt," he said. "I need to get my hands on some balls, follow my assignments. When you come this far and have gone through this much -- well, you just want to finally make it."