Gary Zimmerman has returned, as loquacious as ever.

The seven-time Pro Bowl offensive tackle, who ended his brief retirement on Tuesday, was on the practice field with the Denver Broncos on Wednesday and hoped to appear for 25 to 30 plays in Sunday’s game against St. Louis.

But as for his motives in resuming his career, that will have to come from other sources. Zimmerman, as has been his habit since being acquired by the Broncos from the Minnesota Vikings in 1993, declined to speak with the media.

Zimmerman, 35, retired at the end of the 1996 season after playing with pain in both shoulders and having surgery on his left shoulder in the 14th week of the season. He left open the option of returning, but didn’t tell Broncos coach Mike Shanahan he felt healthy enough until after Denver’s 35-14 win over Seattle on Sunday.

Shanahan said he understood that San Francisco and Oakland both made contract offers to Zimmerman. Instead, the 6-foot-6, 294-pounder signed a four-year, $13 million contract with Denver on Tuesday that, according to a league source, includes a deferred $2.8 million signing bonus.

Zimmerman’s 1997 base salary will be only $200,000.

Young resumes practice

Given a clean bill of health after taking a week off due to his latest concussion, Steve Young resumed practicing with the San Francisco 49ers, and barring any setbacks, will start Sunday’s home opener against the New Orleans Saints.

“Obviously, head injuries are very serious and the fact that I’m showing a propensity to them also is a very serious thing,” Young said. “With that said, they’ve given me clearance to play football and I intend to go play some football.”

Around the league

Green Bay’s Mark Chmura, who was expected to miss 4 to 6 weeks when he tore a ligament in his left knee in the season opener, is listed as questionable, meaning he has a 50-50 chance of playing against the Dolphins… . San Diego Chargers quarterback Stan Humphries, trying to bounce back from a dislocated left shoulder, returned to practice and appears to have a good chance of playing in Sunday’s home opener against Carolina… . Kerry Collins resumed working out with the Carolina Panthers’ first-team offense, increasing the possibility that he might play Sunday against the San Diego Chargers. Collins, whose jaw was fractured in two places by a hit from Denver linebacker Bill Romanowski on Aug. 9, still has not received medical clearance to return to game action… . Brian Williams, the veteran New York Giants center who has been sidelined since being poked in the right eye during practice on July 21, will undergo surgery Friday. Williams sustained an infra-orbital fracture of the eye when poked by tackle Bernard Holsey on the third day of training camp. He has regained normal vision when he looks straight ahead but he starts seeing double in the injured eye when he either lifts or lowers his head slightly… . Buffalo Bills linebacker Gabe Northern has appealed a $7,500 fine by the NFL for a hit against Minnesota Vikings quarterback Brad Johnson.