According to the Red Sox' then-general manager, Lou Gorman, the trade made sense at the time. Gorman spent the ensuing years defending the decision-making process that led up to the Bagwell trade. In his 2005 autobiography, One Pitch from Glory, Gorman noted that Boston already had Wade Boggs at the major league level at third base, and had rated prospects Tim Naehring and Scott Cooper higher than Bagwell on the organization's depth chart. Bagwell had seen some time in the minors at first base, but he was blocked from that position by Mo Vaughn. Gordon pursued Andersen only after receiving assurances from MLB's player relations committee that Andersen would not be lost to the new-look free agency. Nevertheless, the trade is considered one of the most one-sided trades in baseball history. Not only did the Red Sox lose Andersen to free agency after one month, but Naehring and Cooper were both out of baseball by 1997.
In February 2005, Bagwell and Biggio were jointly inducted into the Texas Sports Hall of Fame. Shortly after the 2005 season began, the chronic arthritic condition in his shoulder that had begun in 2001 finally sidelined him, rendering him inactive for three-quarters of the season. The former Gold Glove winner was now subjugated into a defensive liability with severely restricted throwing ability, forcing him to "push" the ball instead of throwing it. Teams began taking advantage of his defensive increased weakness. Once possessing great ability to throw out the lead runner at third base ahead on bunt plays, Bagwell found it difficult to practice with the other infielders between innings.
After having played 4,714 games and their entire major league careers together in Houston, Bagwell and Biggio appeared in their first World Series in 2005. Bagwell was the Astros' designated hitter in the first two games against the White Sox at U.S. Cellular Field, and a pinch hitter in the two games played in Houston at Minute Maid Park. His last official major league plate appearance was in the seventh inning of Game 4, when he pinch hit for pitcher Brandon Backe and grounded out. The White Sox won this contest to sweep the Astros and secure the championship. With contributions of only a partially healthy Bagwell, the White Sox outscored the Astros by a combined six runs, the lowest scoring differential in World Series history. Together with Biggio, Bagwell received Baseball America's Lifetime Achievement Award after the 2005 season.
Per Baseball-Reference.com, Bagwell's 79.6 Wins Above Replacement (WAR) rank sixth-most all-time among first basemen, trailing only Lou Gehrig, Albert Pujols, Jimmie Foxx, Cap Anson, and Roger Connor. Bagwell is fourth among those who have played since 1900, and the only first baseman with a higher WAR since World War II is Pujols. In the final 12 seasons of Bagwell's career, Houston finished in first or second place in the National League Central division 11 times, winning four division titles and qualifying for the playoffs six times, culminating in his lone World Series appearance in 2005. One of the most consistent players in history, he produced at least 4.7 WAR per season in each of his first 11 seasons, and no fewer than 3.7 in all except his final and 15th, which was abruptly cut short by shoulder injury. He spent the first nine of seasons of his career (1991–99) playing home games at the Astrodome, notorious for its reputation as the toughest park in which to hit when baseball was still played there. However, during those nine years, his production was nearly identical at home (.303 average/.421 OBP/.546 SLG) as it was on the road (.305 average/.412 OBP/.544 SLG). In that same period of time, his 160 OPS+ was fourth behind Bonds, McGwire, and Frank Thomas; his 56.7 WAR third to Bonds and Ken Griffey Jr. From 1994 to 2000, a span including his age-26 through age-32 seasons, he averaged 41 home runs and 41 doubles per 162 games while batting .309, .433 OBP, and .593 SLG for a 167 OPS+.