On October 22, 2019, the Patriots shipped their second-round pick in the 2020 NFL Draft to the Atlanta Falcons in exchange for Sanu. The Patriots were in the middle of a playoff hunt and had one of the worst receiving groups in the league. The move was an attempt to get Tom Brady another reliable target. It didn't work.
Sanu played eight games for New England in 2019, making six starts. He caught 26 passes for 207 yards and had only one touchdown. In the Patriots' Wild Card Round loss to the Tennessee Titans, Sanu had one reception for 11 yards.
Despite being a disappointment in 2019, Sanu was expected to be part of the team's receiving corps in 2020. Without any real marquee names other than Julian Edelman, Sanu should have easily won a spot in the rotation. That didn't happen.
Oh, and that draft pick the Patriots shipped to Atlanta? It wound up being the 55th selection. The Falcons flipped it (along with a fifth-rounder) to the Baltimore Ravens in exchange for tight end Hayden Hurst (a former first-rounder) and a fourth-round pick. The Ravens selected J.K. Dobbins with the 55th pick.
The Patriots could have used that pick to improve a roster with a lot of holes. Instead they essentially gave away a second-rounder for virtually no return.
While Belichick has made questionable trades before, this is easily his worst. Trading Chandler Jones away for Jonathan Cooper and a second-round pick is likely the only other competition for that title. Cooper never played a down for the Patriots and they traded the second-round pick for third- and fourth-round selections.
Still, the Sanu deal was worse. At the very least you could say the Jones trade came with salary cap implications because he is currently earning $16 million from the Cardinals. The cash-strapped Patriots could have acquired cheap talented with the pick they sent to Atlanta, but instead have nothing to show for it.