Vikings coach Mike Zimmer said the second-year player will not return to practice this week ahead of the team's final preseason game on Thursday. Elflein was placed on the preseason physically unable to perform list on July 25 and has remained there since.
Elflein had two surgeries in the offseason after fracturing his left ankle in the NFC Championship Game and injuring his shoulder in Atlanta in December 2017.
The center has been limited to working out with trainers in the weight room and on a rehab field over the past month. There was optimism earlier in the preseason that Elflein would be back at some point in August, but that has not panned out.
"He's going to practice when he's ready to go," Zimmer said. "I don't know when that's going to be."
A trade to bolster offensive line depth has felt inevitable for weeks. The Vikings executed one on Sunday, sending a 2019 pick to the New York Giants in exchange for center Brett Jones. The future pick is believed to be a seventh-rounder, according to ESPN's Jordan Raanan.
Jones appeared in 30 games for the Giants and has 14 career starts: 12 at center and two at left guard. He spent training camp and the preseason primarily with the second-team offense.
Jones was on the Giants' payroll for $2.9 million this year and was behind Jon Halapio at center. With Will Hernandez at left guard and Nate Solder at left tackle, everything left of center was solidified, making him a depth piece in New York.
With an uncertain timetable for Elflein's return, Jones could compete to start in his place until the former Ohio State product returns. Cornelius Edison, formerly of the practice squad, has been filling in for Elflein since Nick Easton, the team's former backup center, went down with injury.
Zimmer said he does not think Elflein is at risk for starting the regular season on the PUP list, which would require him to stay there for the first six weeks of the season. After that, a five-week window would open in which Elflein would be allowed to begin practicing again. From the day he returns to practice, the Vikings would have a 21-day window to decide whether to activate him to the 53-man roster.
It's a situation the Vikings found themselves in with quarterback Teddy Bridgewater in 2017, who started the regular season on the PUP list and was eventually moved to the active roster for Minnesota's Week 10 win in Washington.
Injuries have affected Minnesota's offensive line throughout the preseason. In addition to Elflein's prolonged absence, the Vikings lost left guard Easton for the season after he underwent surgery to repair a bulging disc in his neck. Right guard Mike Remmers saw his first preseason action against Seattle after injuring his left ankle during the team's fourth practice in training camp.