The Patriots finally got their second-round draft pick under contract on Sunday when outside linebacker Gabe Jacas signed his rookie deal.

Jacas’s absence from the offseason program was an unexpected mystery. All that was known was that he missed almost the entire offseason and the first two days of training camp because of a surgical procedure. Jacas and the Patriots spent nearly three months negotiating, and he was the 256th of 257 draft picks to sign.

Late Monday, the Globe obtained the key terms of Jacas’s contract via an NFL source. It answers some questions about the delay, but also creates others.

The upshot: Jacas still gets the full value of his rookie contract and the full guarantee slotted for the 55th pick. But he signed an injury waiver for his left knee covering the 2027 and 2028 seasons that would allow the Patriots to void his guarantees should he reinjure that knee.

Read Ben Volin's full story at Globe.com/Sports.