UPDATE: Moore believes signing with the Detroit Lions is a great opportunity

ALLEN PARK -- The Detroit Lions have signed undrafted Boise State quarterback Kellen Moore.

Moore (6-foot and 197 pounds) was not selected in this year's NFL Draft, but signed by the Lions, according to NFL Network's Ian Rapoport.

With the addition of Moore, Detroit has three quarterbacks on its roster. Moore could compete for Detroit's third-string quarterback position if the Lions sign another passer this offseason. The Lions lost third-string backup Drew Stanton in free agency.

Moore was 50-3 as a college starter at Boise State. Last season, Moore was 326-of-439 (74.3 percent) for 3,800 yards, nine interceptions and a career-best 43 touchdowns. In 2010 as a junior, Moore was 273-of-383 (71.3 percent) for a career-high 3,845 yards, 35 touchdowns and six interceptions. He finished fourth in the Heisman voting (first Bronco ever invited to the ceremony). Moore also earned First Team All-American and All-WAC honors.

In Moore's four-year career, he threw for 14,374 yards, 140 touchdowns and 26 interceptions.

Moore is left-handed, which will place a premium on Detroit's right tackle position if he eventually makes the team.

In addition, the Lions have signed Elon guard Rodney Austin (6-foot-3 and 308 pounds), according to according to Mark Magazu, his agent.

Austin ran the 40-yard dash in 5.25 seconds at his pro day workout.

Here is former NFL coach Jon Gruden's QB Camp with Moore, which aired on ESPN: