A number of receivers, most notably Notre Dame's Michael Floyd, distinguished themselves at Lucas Oil Field.
Others who worked out well included Georgia Tech's Stephen Hill (4.36-second 40-yard dash), Stanford's Chris Owusu (4.36), Wake Forest's Chris Givens (4.41), Illinois' A.J. Jenkins (4.39), California's Marvin Jones (4.46), Fresno State's Devon Wylie (4.39) and Wisconsin's Nick Toon (4.54).
But no one created a bigger buzz than Floyd, who may have emerged as the favorite to be the second receiver taken after Oklahoma State's Justin Blackmon, who elected not to run.
The biggest question about the 6-foot-3, 220-pound Floyd had been speed, and he ran a 4.47 40.
"He's the second-best receiver in the draft," one AFC front office man said.
The NFC general manager indicated he still would rank Baylor's Kendall Wright ahead of Floyd, even though Wright ran a disappointing 4.61. Wright is known as a speed receiver based on his game tape, and some believe his slow times were attributable to poor track form.
Floyd will force scouts to go back to Notre Dame game tape to see if they believe he can play anywhere near as fast as he ran. They were skeptical Sunday.
"He's a 4.5 guy on the field is what he is," the AFC front office man said.
A second NFC general manager said he could see Floyd's vertical speed when he gets upfield, but it doesn't show up until he gets moving. He has what scouts call "gradual speed," and isn't the most explosive player.
"He surprised me with how fast he ran," said a third NFC general manager, Jerry Reese of the Giants. "He does not play that fast. In my notes, I said even when he ran his routes (Sunday) after he ran the 40, he didn't run with that same kind of speed.
"Guys can manufacture 40s. You have to be careful about 40 times. But he's one of those guys who is so big he can still take balls off guys when he's covered. That's a unique quality he has. He's an interesting guy."
Still, Floyd undoubtedly helped himself.
Floyd's workout might have assured he is picked somewhere between the 10th and 20th selections of the first round. Among the teams picking ahead of the Bears who could use Floyd are the Bills (10th pick) and Chargers (18th), assuming San Diego loses free agent Vincent Jackson.
Some teams will be more wary of Floyd because he has had three brushes with the law over alcohol.
"We met with him," the AFC front office man said. "He has a history of year after year of mistakes. How many is he going to make? I don't know if he gets it yet."
The first general manager said, "I think most teams are OK with his character."
Besides Floyd and Wright, other receivers who could go in the second half of the first round include Hill, Givens, Louisiana State's Rueben Randle, Rutgers' Mohamed Sanu and South Carolina's Alshon Jeffery.
Of that group, only Randle distinguished himself Sunday. Sanu ran a 4.67 40 and Jeffery did not run.
Jeffery weighed in at 215, down more than 15 pounds from his playing weight during the season, but it wasn't enough to impress scouts. They said he did poorly in interviews and appeared as if he had not been lifting weights.
Hill could be a late riser. He caught only 28 passes but averaged 29.3 yards per catch. He is considered a bit raw, but his speed, combined with a 6-4 frame, is intriguing to NFL teams.