Gaffney, a sixth-round draft choice out of Stanford, sustained a season-ending knee injury in a practice Friday.
The claiming of Gaffney is similar to what the Patriots did two seasons ago with tight end Jake Ballard, who was waived by the Giants with the intention of placing him on injured reserve that year. But before the Giants could place Ballard on IR, he had to clear waivers, per NFL rules when teams are under the 90-man roster limit, and the Patriots claimed him.
"The bottom line is Tyler's injury is a season-ender. It's not a little tear that could be scoped and he'd be back in three weeks," Panthers general manager Dave Gettleman told the Charlotte Observer. "This was a legitimate, season-ending injury. We have Jonathan Stewart, who's not practicing, and we needed the roster spot. Plain and simple. ... This is a very competitive business, and people are going to try to improve their team within the rules. And this is within the rules."
The Patriots inherit Gaffney's contract, which runs through 2017 and calls for base salaries of $420,000, $510,000, $600,000 and $690,000.
Similar to Ballard, the Patriots are likely to keep Gaffney on their 90-man roster, before moving him to IR when rosters are reduced and a player doesn't have to go through the waiver process. That means the team would pay him $420,000 for 2014 for the chance to work with him in 2015 and beyond. Three of the Patriots' top running backs this year -- Stevan Ridley, Shane Vereen and Brandon Bolden -- enter the final year of their contracts.
Gaffney will undergo surgery to repair the torn lateral meniscus in his left knee and will miss the rest of the season. He suffered the injury on his first play of Friday night's practice.
Gaffney had 330 carries for 1,709 yards last season at Stanford. In 486 carries in college he never had an injury.
Information from ESPN.com's David Newton contributed to this report.