LONDON -- Aldon Smith's willingness to voluntarily enter a treatment facility the past month will lessen whatever discipline the NFL imposes on the 49ers' embattled linebacker, league commissioner Roger Goodell said Saturday.

"Yes, it will be a factor, for sure," Goodell responded.

Smith, who was involved in an alleged drunken-driving accident Sept. 20, will miss his fifth straight game when the 49ers play the Jacksonville Jaguars on Sunday at Wembley Stadium.

Smith's estimated return remains uncertain, as does a potential suspension, if there is one at all.

"Certainly, the issue here isn't to discipline players. It's to stop the behavior," Goodell said after a fan forum. "Aldon has voluntarily said, 'I need help.'

San Francisco 49ers Aldon Smith (99) warms up before the game against the Indianapolis Colts at Candlestick Park in San Francisco, Calif., on Sunday, Sept.
San Francisco 49ers Aldon Smith (99) warms up before the game against the Indianapolis Colts at Candlestick Park in San Francisco, Calif., on Sunday, Sept. 22, 2013. (Josie Lepe/Bay Area News Group) ( Josie Lepe )

"We're obviously there to support him, and the 49ers did a great job getting him into a facility to try to get help. We support that."

Smith, a third-year sack specialist, also could be facing further discipline because of felony weapons charges filed against him recently by Santa Clara County prosecutors.

The 49ers drew criticism for playing Smith only two days after his single-car accident in San Jose's Silver Creek neighborhood at 7 a.m.

Asked for his view on Smith playing that game, Goodell explained the league's difficulty to intervene.

"We've made a couple of proposals to our union that we should take quicker action. But they've resisted that," Goodell said. We have to operate within the context of the collective bargaining agreement and joint drug program. That's something we weren't in position to do."