30-year-old Charles Johnson tries to haul in one last comeback — this time, with the Eagles | Bob Ford

It is August in the NFL, the season of sun-warmed hope, and wide receiver Charles Johnson has both a uniform and a chance. At the age of 30, with a career journey that has fishtailed onto the gravel more than once, he doesn’t ask for much else.

“I’m just excited to be out here playing at a high level, not putting too much pressure or too much thought into it,” he said after practice this week, having followed a long workout of receiving drills with a session of catching tennis balls as they were shot from close range. “I’m enjoying my teammates and enjoying each day. That’s what I’m here for. The decisions are made upstairs. If things don’t work out, I’ve just got to be sure I left everything on the field.”

If things don’t work out, Johnson will recognize the feeling. Each step forward in his career, each patch of sunlight through the clouds, has usually been followed by a quick downturn in the weather.

Take this spring, for instance. Johnson was playing in the Alliance of American Football for the Orlando Apollos. He was eager to show NFL scouts in that setting that his right knee, surgically repaired twice, was sound and could hold up through a full season.

Well, it couldn’t have started much better. The Apollos began the season 7-1, the best record in the league, and Johnson had caught 45 passes for 687 yards, including a seven-reception game for 192 yards, which was (and will remain) the AAF record.

His knee felt great. His speed (4.39 in the 40 coming out of college) was still there, and there was even talk Johnson was among the leading contenders for the league’s inaugural most valuable player award.

Then, just before going out to the practice field one morning, head coach Steve Spurrier addressed the team.

“He said, ‘Hey, guys. We’re not going to take the field. There’s some stuff going on,’ ” Johnson said. “It was sad to see how it ended. We had a great team and I thought the league had a bright future for young guys who wanted to grow into the game, or veterans like me who wanted to show teams they had come back from injury. It was very emotional for me.”

The AAF folded quickly, but several NFL teams had seen enough, including the Eagles, to reach out to Johnson about taking a shot at camp. He chose the Eagles because some former teammates and friends, including Torrey Smith and Mike Wallace, told him it was a solid organization that does things the right way.

“It sounded like a good spot,” Johnson said. “I’m not thinking about the numbers. I just want to go out and see what I can do.”

From the start, what Johnson could do was run fast and catch a football. His college path went from Eastern Kentucky, where he was suspended for “immature things,” to Antelope Valley Community College, to two seasons at Grand Valley State, a Division II school in the Great Lakes Intercollegiate Athletic Conference.

Despite gaining more than 1,000 receiving yards each season at Grand Valley, Johnson wasn’t invited to the NFL scouting combine. Apparently, receptions against Saginaw Valley and Ferris State didn’t cut much ice with the league.

In any case, he showed enough at his pro day workouts to be taken in the seventh round of the 2013 draft by the Packers. He was assigned to the practice squad at the end of training camp and, one month later, was signed away by the Browns to be placed on their active roster.

That was the good part. The bad part was his initial physical in Cleveland revealed an ACL tear in his right knee. This was news to the Packers and to Johnson, and it was certainly news to the Browns, although they tended to have things like that happen a lot.

A year later, following surgery and recovery, Johnson was on the Cleveland practice squad when he was signed away by the Vikings. Amazingly enough, he showed up healthy and played 39 games during the 2014-16 seasons for Minnesota, catching 60 passes for 834 yards (a very decent 13.9 average gain) and two touchdowns.

The following year he was signed in March by the Panthers and then released in July when his knee required another surgery. Last year, he was a camp receiver for the Jets before being cut just before the start of the season.

After his brief renaissance in the AAF, Johnson has landed here, his sixth NFL organization, and while the odds aren’t necessarily in his favor, they aren’t much worse than at his five previous stops.

“I think I’m getting younger. That’s what I feel like,” Johnson said. “In the NFL, they kind of harp on your age a little bit, but I feel as fast as I have ever been, and explosive as I have ever been. I’ve battled through injuries, and when you know you’re injured, it’s totally different. I feel fresh, and when you know what you can do as a player when your body is right, your mind is in a different place.”

He will have that opportunity in the preseason, starting Thursday against the Titans. The games represent his real opportunity to finish the comeback, and is perhaps his last one, not just with the Eagles but with all the other NFL teams who will be reviewing these games.

The field is crowded with receivers here, and a lot may depend on whether the team opts to keep five or six at the wide and slot positions. DeSean Jackson, J.J. Arcega-Whiteside, Alshon Jeffery, Nelson Agholor, and, health-permitting, Mack Hollins are sure things. That’s five right there.

Johnson is in the next tier of hopefuls, one that includes Greg Ward, Marken Michel, Braxton Miller, Carlton Agudosi, and Shelton Gibson. It’s a crowded bubble, obviously, and will burst for nearly all of them.

“I just want to show people what I can do,” Charles Johnson said.

It is all he asks now, very aware that requesting more is only tempting fate.

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