The person spoke to The Associated Press on condition of anonymity Saturday because NBA rules prevent the deal from becoming official until July 10.
On his Twitter page, Aminu posted the message: "Excited to be back in NOLA."
The extension was first reported by the Times-Picayune, which said the deal was for $3.7 million.
The 6-foot-9 Aminu, heading into his fourth NBA season, started 71 games last year, playing mostly at small forward. He averaged career highs of 7.3 points and 7.7 rebounds per game, with season-highs of 20 rebounds against Dallas on April 17 and 18 points against Boston on Jan. 16.
Aminu was drafted eighth overall out of Wake Forest in 2010 by the Los Angeles Clippers. He came to New Orleans as part of a 2011 trade that sent Chris Paul to the Clippers, and which also brought shooting guard Eric Gordon to the Pelicans, who were then called the Hornets.
Aminu's first chance to start regularly came last season, and coach Monty Williams spoke highly of Aminu's rebounding and all-around athletic ability. But Aminu was unable to demonstrate that he could provide consistent scoring from the wing position, and the Hornets went into this offseason with both Williams and general manager Dell Demps acknowledging that the club was looking to acquire another small forward.
A trade that will bring Tyreke Evans to New Orleans once it's official should help the Pelicans in that area when matchups allow. However, the 6-6 Evans appears more suited to playing shooting guard and would likely have a height disadvantage if forced to play heavy minutes on the wing.
Demps said during the NBA draft that he expected to be very active in free-agency. His next moves could include not only the acquisition of another wing player, but also a center.
Robin Lopez, who started at center for New Orleans last season, was sent to Portland as part of the three-team deal involving Evans that was agreed upon on Thursday -- and also sent guard Greivis Vasquez to Sacramento.