On October 16, 2017, Aldridge signed a three-year, $72.3 million contract extension with the Spurs, with only $7 million guaranteed in the final year of the extension. Two days later, in the Spurs' season opener, Aldridge had 25 points and 10 rebounds in a 107–99 win over the Minnesota Timberwolves. On November 14, 2017, he scored a season-high 32 points in a 97–91 win over the Dallas Mavericks. On November 27, 2017, he set a new season high with 33 points in a 115–108 win over the Mavericks. Two days later, he set his San Antonio high with 41 points in a 104–95 win over the Memphis Grizzlies. On January 23, 2018, he was named a Western Conference All-Star reserve, becoming the first Spurs player who didn't play his rookie season in San Antonio to make the All-Star team since Artis Gilmore in 1986. Three days later, in a 97–78 loss to the Philadelphia 76ers, Aldridge grabbed his 7,000th career rebound, becoming the only player in the NBA with 16,000-plus points and 7,000-plus rebounds since he entered the league in 2006. On March 17, 2018, he had a 39-point effort in a 117–101 win over the Minnesota Timberwolves. On March 21, 2018, in a 98–90 win over the Washington Wizards, Aldridge became the 27th player in league history with 900-plus blocks and 16,000-plus points in his career—the only player to accomplish that feat since he began his career in 2006. Two days later, he had a career-high 45 points in a 124–120 overtime win over the Utah Jazz. His 28 points in the first half were the most by a Spurs in a half since Manu Ginóbili had 28 points against Cleveland in 2008. In Game 2 of the Spurs' first-round playoff series against the Golden State Warriors, Aldridge scored a game-high 34 points in a 116–101 loss. The Spurs went on to lose the series in five games.