Rivers kicked off the morning wowing scouts with a 42-inch vertical jump -- a full eight inches better than any outside linebacker recorded at the Combine in February -- and a 10'7" broad jump that also topped any other linebacker tested in Indianapolis.
Ellis saved his dramatic effort for the 40-yard dash, where in recording times at 5.01 and 5.05 seconds, he shaved nearly three tenths of a second off of his Combine times.
Rivers' efforts weren't limited to leaping, as he also impressed scouts in the 40, recording a 4.57 and 4.51 second times.
"These kids were prepared," Packers general manager Ted Thompson told NFLDraftScout.com. "They have some athletic players here -- everyone knows that. But they also came in very prepared and ready to show what they could do."
Rivers, who didn't work out at the Combine due to an ankle injury, had the most to prove Wednesday. While most viewed him as the top linebacker of the class, strong workouts by Penn State's Dan Connor and Tennessee's Jerod Mayo left Rivers vulnerable -- and needing a strong performance.
When told Connor graded himself as a "13" on a scale of 1-10 following his workout, Rivers offered his own self-assessment.
"I'd give myself a 6 or 7," Rivers told NFLDraftScout.com. "My vertical, broad and 40 were good, but I didn't do as well in my positional drills as I would have liked to have done."
Ellis was quite proud of his performance. After a senior campaign in which he was voted a unanimous All-American selection and the Pac-10 Defensive Player of the Year, Ellis' stock was never higher than following a dominant showing at the Senior Bowl. Poor times at the Combine, however, had his stock slipping.
He felt his improved workout Wednesday would force scouts to rethink their perception of his athleticism.
"I think it has to mean something," he said. "If the people ranked ahead of me put up one number and I put up a better or faster number; that has to mean something. I'm a competitor. For the coaches and scouts that came today, I think they saw that."
A host of other potential first-day picks worked out at USC on Wednesday:
--Mackey Award winner Fred Davis, who elected to only compete in the positional drills and bench press at the Combine, secured his position among this year's top tight ends with a solid showing. Davis recorded a 33-inch vertical jump and was twice timed in the high 4.6s in the 40. Most important, Davis caught the ball very well during position drills. In uncharacteristically dropping several passes during drills at the Combine, Davis needed to ease scouts' concerns. He did so Wednesday, contorting his body easily to snatch passes from a variety of angles. To show his versatility, Davis was lined up outside as a receiver, inside as the slot, in motion and in the three-point stance as a typical tight end. In all cases, he caught the ball cleanly, suffering only one drop -- and that was a poorly thrown pass.
--The poor pass to Davis was uncharacteristic of quarterback John David Booty's performance Wednesday. While he doesn't blow anyone away with his arm strength, Booty's accuracy -- especially on post and slant routes -- made life easy on his fellow skill position players looking to impress scouts.
--It was a player thought to be a late-round prospect, however, who caught many scouts off-guard.
Running back Chauncey Washington, used throughout much of his career as a power back due to his muscular 6-foot, 211-pound frame, turned in the surprise performance of the day when he registered a pair of sub-4.4 40s. Stunned scouts immediately began comparing stop-watches, with times ranging from 4.32 to 4.39. Washington, though invited, had elected not to run at the Combine. He had widely been estimated by scouts to have marginal speed. In compiling impressive results in the vertical jump (36 inches), broad jump (9'11") and bench press (18), Washington proved his athleticism is legitimate and not just speed-driven.
"Washington helped himself today," Thompson told NFLDraftScout.com. "He was prepared. He ran well. He looked good in positional drills. Caught the ball well."
--Another late-round prospect who helped his stock considerably was versatile linebacker Thomas Williams. He was invited to the Combine despite starting only 14 of 49 games for the Trojans, and struggled in clocking in at 4.86 seconds. With times in the mid-4.6s Wednesday, however, Williams likely assured himself of being drafted.
Trojans coach Pete Carroll certainly thought so.
"Thomas Williams went to the Combine and didn't run as well as he would have liked and then he runs a time today almost two-tenths faster. His stock, I'm sure, was elevated considerably today."
--Offensive tackle Sam Baker looked good in positional drills, but was considerably slower in the 40 than he had been at the Combine. In Indianapolis, Baker was clocked at a very respectable 5.09. But his first dash Wednesday was timed at 5.49. His second was faster (5.37), but not nearly as good as his previous work.
--Offensive guard Chilo Rachal timed in slower than expected in the short shuttle (4.85) and three-cone drills (7.91).
--Cornerback Terrell Thomas was timed in the mid-4.5s Wednesday after clocking 4.45 at the Combine. In proving he can run in the mid-4.4s earlier, there remain a number of teams who feel he can play cornerback in the NFL, though many feel he'll ultimately be moved to free safety.
--Defensive end Lawrence Jackson elected not to run or jump after a good performance at the Combine, but had a solid showing in positional drills.
Rob Rang is a Senior Analyst for NFLDraftScout.com, distributed by The Sports Xchange.