Wilson explained it was partly a work trip, with daily workouts and throwing sessions, and partly a vacation that allowed the Hawks' offensive duo to bond.
"We were able to go down together to Mexico—safely, and before COVID kind of went crazy," Wilson told reporters. "We were able to spend some time down there, I don't know, five, six, seven days, down there and just getting a lot of work in."
He added: "Kind of cool. I actually got to teach DK how to swim."
Wilson joked Metcalf was a fast study in the water and is now "always in the pool."
"I'm like, 'Don't stay in there too long,'" he said Thursday.
Metcalf is coming off a strong rookie season for the Seahawks. He recorded 58 catches for 900 yards and seven touchdowns while playing all 16 regular-season games. He added 11 receptions for 219 yards and a score in two playoff appearances.
The 22-year-old Mississippi native should once again take on a headline role in the team's Wilson-led passing attack as a starter opposite Tyler Lockett.
Seattle is scheduled to kick off the regular season Sept. 13 when it visits Mercedes-Benz Stadium to take on the Atlanta Falcons.