Otis Grigsby was an all-state selection as a linebacker at Judson High School in Converse, Texas. He went to Kentucky under the assumption that he would continue to play that position.

"I was a great linebacker," Grigsby said. "Then, the coaches told me I could get on the field faster at defensive end. That sounded good, so I switched positions, but I never really learned how to play the position.

"I didn't learn the techniques. I just waited for the snap and ran."

Grigsby was not taken in the 2003 NFL draft. He signed as a free agent with Miami. Rick Spielman was running the Dolphins personnel department, and George Paton was his assistant.

This would pay off 4 ½ years later for Grigsby -- and get him on the field in San Francisco on Sunday to get his first NFL sack. Spielman became Vikings vice president for personnel in May 2006. He brought in Paton this year.

A week ago, the Vikings ran into a crisis at defensive end. Ray Edwards was suspended for failing a steroid test. Erasmus James was headed for a third surgery on his left knee.

Grigsby was on the practice squad in Carolina. He had played in his first four NFL games for the Panthers -- three in September, one in November.

"I was inactive the rest of the time," he said. "They put me on waivers [Nov. 17], then three days later brought me back on the practice squad.

"There was talk I was going back on the active list with the Panthers, but even if they did that, I wasn't going to play."

So, Grigsby was pleased to get the call from Minnesota, and to find himself on the field with some regularity Sunday. In the fourth quarter, he belted 49ers quarterback Shaun Hill, and the loose football landed in the arms of tackle Spencer Johnson.

At the moment, it looked like the Vikings' third interception for a defensive tackle. But it was ruled a fumble -- and then Pat Williams lost his interception when the NFL stats czars ruled on Monday that it was also a fumble.

Grigsby earned a sack and a forced fumble with his hit on Hill, and perhaps another shot at a scrub quarterback, Chicago's Kyle Orton. An appearance on "Monday Night Football" would complete quite an odyssey for Grigsby.

He spent the 2003 season on the Dolphins practice squad. He was waived in the last cut in 2004. "I was young and dumb and didn't do anything," Grigsby said. "I just hung around Miami and worked out."

He signed with Atlanta on Aug. 8, 2005, and was waived 18 days later. Again, he didn't have a team, but he went to work.

"I was a substitute teacher in Gwinnett County outside Atlanta," he said. "I worked with a marketing outfit. And I was a bouncer at a country western bar: Wild Bill's."

Grigsby signed with Carolina on Jan. 4, 2006, after he agreed to go to NFL Europe in Cologne, Germany. "I was even on the practice squad there for half the season, before they realized this guy the Seahawks had sent didn't really want to play," he said. "I played well there."

He came home, went to training camp with Carolina and was cut in late August. Again, he was in football limbo, until the Panthers placed him on the practice squad in December.

Finally, in his fifth season out of college, Grigsby made a team out of training camp. He was active for the opener against St. Louis.

"I hit [quarterback] Marc Bulger on the Rams' last drive, hit him very hard in the chest," Grigsby said. "He fumbled, we recovered and won the game. That was a big play."

Not enough of those followed, and Grigsby soon was back in the NFL's nether world -- inactive, waivers, practice squad. That changed, however briefly, when he hit Shaun Hill with his Sunday best.

"The other guys were saying: 'We need that to be an interception. That will be the first time three linemen have intercepted passes,'" Grigsby said. "And I said, 'Sorry guys, but that's my first NFL sack, and I've been out of college since 2003.'"

Grigsby paused, laughed and said: "Preseason doesn't count. I needed that sack on my record."

Patrick Reusse can be heard weekdays on AM-1500 KSTP at 6:45 and 7:45 a.m. and 4:40 p.m. • preusse@startribune.com