The play happened midway through Wednesday's workout and seemed innocuous enough as Heyward-Bey gingerly walked back to where the rest of the players stood and remained there momentarily.
But after meeting with team trainer Rod Martin, the Raiders' rookie wide receiver slowly limped off the practice fields and into the team's facilities.
"(He) is sore," Oakland head coach Tom Cable said without elaborating. "We don't have any idea what that means because we haven't had a chance to go look at him yet."
It's the second time since being selected with the seventh overall pick in the draft that Heyward-Bey has been hurt. He strained the same hamstring during the May mini-camp and sat out the final two days of practice as a result.
Other news and notes from the OTA workout:
X Quarterback JaMarcus Russell had a typical up-and-down day. He missed some easy throws – overthrowing Marcel Reece on a short flat pattern, sailing another over the head of Johnnie Lee Higgins across the middle – and he also made some nice passes – connecting with wide receiver Shawn Bayes for a 12-yard gain, hitting tight end Chris O'Neill for a first down during the two-minute drill then later drilling a 22-yard completion to Samie Parker.
Most impressive, however, was what Russell had to say after the practice. The Raiders third-year quarterback told reporters he intends to meet with the team's wide receivers and tight ends after the OTAs end so they can continue to work on their timing together.
Russell wants to get away with the receivers and tight ends.
That's encouraging news for head coach Tom Cable, who has asked Russell to take on more of a leadership role with the team this year.
"I think it's a big step," Cable said. "It's kind of what we've been talking about all along, and to hear about that is obviously a positive from a coaches' standpoint. It will be good to hear how that goes and what his plan is."
X Samson Satele continues to take reps with the backup offense while John Wade handles the starting center duties. The former Miami Dolphin still seems to be thinking instead of reacting, which is to be expected since he only recently resumed practicing after undergoing shoulder surgery. Still, I anticipate this battle lasting through the entire preseason; it will easily be the most watched.
X Starting cornerbacks Nnamdi Asomugha and Chris Johnson were both absent, leaving Stanford Routt and John Bowie to handle the starting chores. No reasons were given for their absence.
Same goes for punter Shane Lechler, kicker Sebastian Jankowski, quarterback Andrew Walter, cornerback/kick returner Justin Miller, running back Gary Stevens, safety Michael Huff, defensive end Derrick Burgess and defensive tackle Tommy Kelly.
Wide receivers Javon Walker, Chaz Schilens and Arman Shields, along with second-round pick Mike Mitchell, all attended the workout but did not practice due to various minor ailments.
X Quarterback Jeff Garcia, whose wife recently gave birth to the couple's second child, returned to practice after missing the last two weeks. Considering his time off, Garcia looked sharp for the most part. His passes were crisp, he scrambled out of problems a few times and made a nice completion on the run. During a goal-line drill, Garcia ran a picture-perfect play-fake and hit Parker for a short TD.
Garcia did have his gaffes, too. On one play where the Raiders tried to stretch the field vertically, the veteran quarterback launched a deep pass that landed well past the outstretched hands of wide receiver Nick Miller.
X Rookie wide receiver Louis Murphy and cornerback Jason Horton exchanged words after Horton got the better of Murphy during a team scrimmage. Murphy seemed to take exception with how physical Horton was during the mostly non-contact drill but Horton simply laughed it off and smiled as the rookie walked away grumbling.
X Left tackle Mario Henderson buried cornerback John Bowie on one running play, clearing a huge hole for Darren McFadden to easily burst through.
Tyvon Branch was fired up at Wednesday's practice.
Afterward, an obviously still irked Branch was approached by defensive coordinator John Marshall as he walked off the field but Branch waved Marshall away.
X Hiram Eugene returned to practice after sitting out last week's round of OTAs with a sore back. Eugene took reps alongside Branch with the Raiders starting secondary.