USC’s Tyron Smith adds to his credentials by putting on the pounds

Tyron Smith has simultaneously put on 25 pounds and lightened his load.

The USC offensive tackle no longer has to make the weighty decision of where to watch next month’s NFL draft. He has accepted the league’s offer to await his selection at Radio City Music Hall.

Not so long ago, that would have been a controversial choice. The NFL Players Assn. initially encouraged the elite prospects to snub any such offer from the league, reasoning that those players should not support a league that had locked them out. The decertified union promised to plan an “alternative” celebration in New York.

Video: Sam Farmer and Gary Klein at USC pro day

This week, however, the NFLPA scrapped those plans, announcing it will stage a three-day event that coincides with the draft but doesn’t conflict with the NFL’s broadcast. That opens the door for players such as Smith to attend both events.

“Basically it’s a once-in-a-lifetime opportunity, so just take advantage of it,” Smith said Wednesday at USC’s pro day. “I don’t know who would want to miss it.”

If Smith keeps impressing teams the way he has, he won’t have to wait long to be picked. Many teams see him as the most athletic tackle in the draft, and Smith has answered the main question of scouts — can he get bigger? — by bulking up to 310 pounds. He has never played at more than 285.

“It’s been important to gain the weight so I can feel more comfortable about myself and feel more healthy,” said Smith, who said he envisions playing at 315. “It’s natural weight.”

There were dozens of NFL scouts in attendance at pro day, during which Smith and several other USC players worked out. Head coaches Jason Garrett of Dallas and Hue Jackson of Oakland were there too.

It was the only pro day Garrett has attended, further raising speculation that the Cowboys are interested in taking Smith with the ninth pick. Smith has seven trips planned to visit teams, including a stop in Dallas next week.

Mustain ready to move on

Quarterback Mitch Mustain worked out and spoke publicly for the first time since his arrest on suspicion of selling prescription drugs.

Mustain, 23, will not face misdemeanor charges if he completes a pre-file diversion program that includes a drug-education program, 100 hours of community service and avoidance of another incident with police over the course of one year.

Mustain said he regretted the incident and was satisfied with the outcome.

“I imagine the alternative is a lot more drawn out, a lot more costly,” he said. “So we’ll take what it is and deal with it and work with it as we go.”

Though he termed it “really a non-issue at this point,” Mustain acknowledged that he was prepared for pro teams to question him about it.

The 6-foot-2, 221-pound Mustain has added several pounds of muscle since the end of the season and looked stronger in his throws than at any time during his four years at USC.

Mustain knows he has a lot to prove — “You only have to impress one team,” he said — but said character was not an issue.

“I’m not a problem child,” he said. “It was an isolated incident.”

Asked if he’d learned anything from the incident, he said, “Yeah. Don’t do it again.”

Quick hits

USC’s Oct. 22 game at Notre Dame is scheduled to kick off at 4:30 p.m. PDT. … Receiver Brice Butler, who left the team, said he was considering transferring to Delaware or Tennessee Chattanooga. He said there was a slim chance he would rejoin the Trojans but that he had not had a conversation with Coach Lane Kiffin about it.

sam.farmer@latimes.com

twitter.com/latimesfarmer

gary.klein@latimes.come

twitter.com/latimesklein