Haynes was signed because the Ravens sorely need depth at running back with starter Willis McGahee sidelined along with P.J. Daniels and Cory Ross.
When the Ravens invited Haynes to try out, he was at home in Orlando, Fla., after being released by the Carolina Panthers when training camp opened.
"Of course, anytime you’re sitting at home and somebody calls you off the street and gives you a chance to participate in camp, it’s always a great opportunity," Haynes said. "I just had to be patient.
"It’s tough because you want that chance and I just got cut. If you believe in yourself, you keep praying. Basically, I feel like I can do it all and add game to the special teams."
Haynes rushed for three yards on three carries with Carolina last year, catching three passes for 14 yards.
The 5-foot-10, 225-pound runner was with the Ravens briefly years ago after initially failing his physical when he was signed as an undrafted free agent out of Central Florida.
He has spent the past three years with the Panthers, shuffling back and forth from the practice squad and being allocated to NFL Europe.
Now, he has to learn the playbook.
"It’s all the same stuff, you just got to pick up the terminology," said Haynes, who also returns kickoffs. "I can pick up what they want me to do, how they want me to do it.
The Ravens cut recently-signed cornerback Anwar Phillips to make room for Haynes.
Meanwhile, running back Allen Patrick returned to practice from a mild concussion.
"We had two more guys out there, and it went really well," Ravens coach John Harbaugh said. "Le’Ron McClain was complaining that he wasn’t getting enough reps. He was taking all the reps yesterday."
INJURY UPDATE: Wide receiver Mark Clayton’s right arm is in a sling after injuring his shoulder Friday morning during team drills. It’s unclear how long the starting receiver will be out.
If Clayton is unavailable for next week’s preseason opener against the New England Patriots, the Ravens would likely start rookie Marcus Smith opposite veteran Derrick Mason.
Several players didn’t practice, including: wide receivers Patrick Carter (dislocated left shoulder) and Demetrius Williams (left Achilles’ tendon), safety Ed Reed (shoulder), cornerback Samari Rolle (bereavement), McGahee (left knee), Daniels (cramps), Ross (arm, toe), defensive end Dan Cody (right foot), linebackers Gary Stills (knee) and Terrell Suggs (contract dispute), offensive tackles Oniel Cousins (sprained right medial collateral ligament), Jared Gaither (sprained right ankle), Adam Terry (sprained left ankle) and Joe Reitz (shoulder), tight ends Aaron Walker (leg) and Daniel Wilcox (offseason toe surgery), defensive tackles Haloti Ngata (sprained medial collateral ligament) and Justin Bannan (undisclosed) and nose guard Kelly Gregg (left knee).
Harbaugh said he didn’t know how long Cousins will be out.
Cornerback David Pittman (foot), offensive guard Adrien Clarke (leg) and defensive tackle J’Vonne Parker returned to practice.
READY TO HIT: Outside linebacker Antwan Barnes has registered several sacks, but has to put the brakes on when he approaches the red-jersey wearing quarterbacks.
Against the Patriots, though, Barnes can go full-tilt against the quarterbacks, including Patriots star Tom Brady.
"Red means stop, but the green light will be on Thursday night," Barnes said. "I doubt Tom Brady will be out there long in a preseason game, but I’ll try to hit him if he’s out there."
QUICK HITS: Quarterback Troy Smith was about an hour late for practice as he was delayed while trying to provide a urine sample for a random NFL drug test. "There’s an issue with the new drug-testing policy that’s in place," Harbaugh said. "It’s very strict, very stringent and they have to get the drug test done before they can come out and practice in the morning or they can’t get it done. Sometimes, it takes guys a little longer to get it done and it took Troy a while to get that taken care of." … The Ravens’ return specialist candidates struggled with ball security as running back Ray Rice dropped two punts and Yamon Figurs dropped one. … Kyle Boller was intercepted twice by middle linebacker Ray Lewis. … Rookie safety Haruki Nakamura batted down consecutive passes intended for tight end Todd Heap during a red-zone drill. … Former Ravens offensive tackle Orlando "Zeus" Brown attended practice. He greeted Harbaugh and general manager Ozzie Newsome with hugs on the field. Harbaugh said he didn’t try to coax Brown out of retirement. "That’s funny," he said. "I actually said: ‘Gosh, you look really good. We need tackles.’ My guess is if we would have asked, he would have suited up." … The Ravens had 15 military representatives join their huddle Thursday afternoon to end practice. "That was so cool," Harbaugh said. "That group had been to Iraq recently and got back safe and sound and were in great spirits. It was great for our players. They’re out here in this 90-degree heat, and these guys and gals have been over in Iraq in 120-degree heat. It was a good message for our team."