Underwood, 23, is the second defensive back taken in the draft by the Packers. Green Bay selected Nick Collins of Bethune-Cookman in the second round of the draft.
"The coaches let me know that there's a good opportunity for me out there," Underwood said. "If I work hard there's a chance that I'll play a little bit this year."
Underwood was one of the fastest defensive backs in the Mountain West Conference (4.38 in the 40-yard dash). He is a solid wrap-up tackler who is very effective covering ground in the open field.
Underwood redshirted in his first season on the San Diego State campus in 2000. He played in 10 games, seeing action mostly on special teams in 2001, finishing with 13 tackles (10 solos) and a fumble recovery. Underwood took over free safety duties in 2002. He ranked second on the team with 83 tackles (46 solos), two stops for losses, a forced fumble, three interceptions and five pass breakups.
Underwood followed with 68 tackles (43 solos), a forced fumble, three stops behind the line of scrimmage, two pass thefts and four deflections as a junior. He ranked fourth on the team with 58 tackles (31 solos) in his final year. He also caused and recovered a fumble, batted away 10 passes and intercepted two others in 2004. For his career, he earned 36 starting assignments in 46 games. Underwood recorded 222 tackles (130 solos) with a 2-yard sack and eight stops for losses of 19 yards. He recovered two fumbles, caused three others, gained 137 yards with a touchdown on seven interception returns and deflected 20 passes. He also returned three kickoffs for 32 yards. Underwood also will be competing against veterans Arturo Freeman, Earl Little, Mark Roman and Todd Franz for the right to start at safety.
Poppinga, 25, began at defensive end for BYU but was moved to outside linebacker his senior season because of his above-average speed. Poppinga comes from a sports-oriented family with close ties to BYU and Utah State. His father, Dennis, played tight end at BYU from 1968-1971.
Poppinga's older sister, Tara, played volleyball at Utah State. His older brother, Casey, was a tight end at Utah State. His younger brother, Kelly, plays linebacker for BYU.
The Packers are expected to use Poppinga at outside linebacker.
Poppinga shifted to left outside linebacker in a 3-3-5 defense as a senior, garnering All-MWC first-team honors for the third consecutive year. He ranked third on the squad with a career-high 79 tackles (35 solos), adding five sacks, 12 stops for losses, five pressures and a fumble recovery. In 47 games with the Cougars, Poppinga started 25 times. He finished his career with 193 tackles (99 solos), 19 sacks for minus-120 yards, 39 stops for losses of 162 yards and nine pressures. His 19 sacks rank seventh on the school's career-record list. He also recovered five fumbles, caused four others, intercepted a pass and deflected another.
Poppinga saw action in every game as a reserve at right defensive end for Brigham Young in 2001. He recorded 10 tackles and recovered a fumble that year. He earned first-team All-Mountain West Conference and Academic All-MWC honors as a sophomore. That year, he started only two games, but posted 49 tackles (25 solos) while leading the team with eight sacks and ranking second with 14 stops behind the line of scrimmage. He also caused three fumbles. As a junior, he manned the right defensive end position, picking up All-MWC first-team accolades. He registered 55 tackles (34 solos), led the team with five sacks, ranked second with 13 stops for losses and recovered two fumbles.
The Packers obtained the 126th overall pick from Carolina in a trade on Saturday, but dealt it to Philadelphia for three selections – the 167th, 175th and 245th overall picks.