Wojnarowski also notes the deal includes a player option.
Aldridge took to Twitter to write "I'm happy to say I'm going home to Texas and will be a Spur!! I'm excited to join the team and be close to my family and friends."
According to Wojnarowski, Aldridge told the Trail Blazers on July 3 that he was down to the Spurs and Suns and agreed to join San Antonio on the morning of July 4.
Wojnarowski reported that the Spurs made a "powerful" presentation on July 1, placing them as firm front-runners for the coveted forward, ahead of other interested teams like the Rockets, Mavericks, Lakers and Heat.
While the Portland Trail Blazers could offer more than $109 million over five years compared to competitors' max offers of roughly $81.2 million over four years, the 29-year-old power forward decided to join a team with proven postseason success and an obvious role for him moving forward as the Spurs' nucleus continues to age.