FOXBOROUGH, Mass. -- New England Patriots cornerback J.C. Jackson, who was second in the NFL last season with nine interceptions, officially signed his second-round restricted-free-agent tender on Friday.

The tender locks Jackson into a one-year, $3.38 million contract for 2021, and then he is scheduled to be an unrestricted free agent next offseason.

The deadline for teams to sign restricted free agents to offer sheets is April 23, and others around the NFL could soon be following Jackson's lead. Green Bay tight end Robert Tonyan, who was also tendered at the second-round level after catching 11 touchdowns last season, is among the most notable.

One line of thinking was that players such as Jackson and Tonyan might draw interest from other teams, which could have signed them to offer sheets and then would have surrendered a second-round draft pick if the players' teams declined to match.

But with salary-cap space at a premium across the NFL, there hasn't been much traction with the restricted-free-agent market this offseason.

Jackson, 25, has been a success story in New England after initially joining the team as an undrafted free agent out of Maryland in 2018. He has played in 45 regular-season games, with 22 starts, and has 17 interceptions.