As a senior at Stanford last year, Doug Baldwin finally blossomed.

He had 58 catches - 20 more than he managed in his first three seasons combined - and added 857 yards and nine touchdowns to help the Cardinal to a 12-1 season.

Then-Stanford tackle Derek Hall was so impressed by his teammate's coming-out party that he expected it to continue in the NFL.

"He's just really made a lot of big plays last year, which made me feel like - yeah, he's going to do well at the next level," said Hall, a member of the 49ers' practice squad. "I really thought that whoever got him was going to get a real steal."

In retrospect, 49ers head coach Jim Harbaugh, Baldwin's coach during his four-year college career, wishes he shared Hall's foresight.

Harbaugh has four of his former college players on San Francisco's eight-man practice squad, but Baldwin is playing - and thriving - in Seattle for former USC head coach Pete Carroll.

The 49ers visit Seattle on Saturday. Baldwin, an undrafted free agent, leads the Seahawks in receptions (46), yards (731) and shares team-high honors with three touchdowns. Baldwin could become the first undrafted rookie since 1960 to lead a team in both receptions and receiving yardage.

"I should've drafted him," Harbaugh said in a conference call with the Seattle media this week. "Kicking myself for not doing that."

Harbaugh and the Niners, of course, aren't alone.

Thirty-one other NFL teams passed over Baldwin in the NFL draft based on his lack of size (5-foot-10, 189 pounds), so-so speed (he ran in the high 4.4s in the 40-yard dash) and his lack of production before his senior season.

Baldwin said Harbaugh contacted him during the latter stages of the draft and said the Niners would be interested in signing him as an undrafted free agent. When the lockout was lifted, however, Baldwin said San Francisco's interest wasn't as strong as some of the other teams that pursued him. The Seahawks were the first team to contact him.

"I just felt that Seattle was the best opportunity for me to come in and win a job," Baldwin said.

Baldwin did so by sharing team-high honors with nine catches in the preseason. Then, in his first NFL game, he had four catches for 83 yards and scored on a 55-yard catch in the fourth quarter of a season-opening 33-17 loss to the 49ers.

Carroll coached against Baldwin in college, but said he now appreciates many of the rookie's intangibles after watching him on a daily basis.

"What separates him now is his competitiveness," Carroll said. "He plays with a chip on his shoulder and a toughness about him. He doesn't back down from any challenge and he's just got a great attitude that fits our style of play."

Said 49ers offensive coordinator Greg Roman, an assistant at Stanford during Baldwin's final two years in college, "Maybe he's not the biggest guy, but he's just such a scrappy competitor. When he puts his mind to something, he just won't be denied."

Baldwin's rugged style has translated well to special teams. In a 30-13 win over the Rams on Dec. 12, Baldwin had a 37-yard kickoff return, blocked a punt that set up a touchdown and downed a punt at St. Louis' 6-yard line, a performance that earned him the NFC's Special Teams Player of the Week award.

Baldwin didn't practice Thursday because of a nagging ankle injury, but Carroll has told the Seattle media that he expects his wide receiver to play against the 49ers.

For his part, Hall expects that his former teammate, bypassed by his former college coach and 31 other teams in April, will have that same chip on his shoulder.

"He's probably always felt that people weren't giving him the level of respect that he deserves," Hall said. "And I'm sure he still feels that way."