Sheldon Richardson on Sunday repeatedly showed the skills that the Vikings believed he could unleash when they sought him during free agency.

The 2013 first-round pick of the Jets who spent 2017 with the Seahawks before signing a one-year deal with the Vikings.

Vikings Head Coach Mike Zimmer liked what he saw and even kidded the 3-technique defensive tackle that he "hadn't seen that guy before."

Maybe amend by adding a qualifier to "hadn't seen that guy in Purple before."

"Sheldon played very well," Zimmer said. "Rushed the passer well. Played the run good."

Richardson split Minnesota's first sack of the 2018 season with Everson Griffen. The play is in the video below.

First Quarter, 3:27 remaining

First-and-20 at the SF 15:

The Vikings are in their base defense a play after a holding penalty against the 49ers. Minnesota simply opts to rush its front four against San Francisco's five offensive linemen.

The 49ers start in the shotgun formation, with fullback Kyle Juszczyk next to quarterback Jimmy Garoppolo. The play sends Jusczyk out on a route, leaving no one to help.

San Francisco matches left tackle Joe Staley against Griffen and double-teams Linval Joseph with LG Laken Tomlinson and C Weston Richburg. That leaves Richardson with a 1-on-1 against Mike Person and Danielle Hunter with a 1-on-1 against Mike McGlinchey.

Richardson drives Person backward and creates space so quickly that Richburg doesn't have enough time to shift from helping with Joseph to stymie Richardson. Even though Richburg gets a piece, Richardson is able to keep going toward Garoppolo and make contact before Griffen surges to finish the play.

Richardson's press box stat line was six tackles, one-half sack and three quarterback hits.

The film was likely even better in the eyes of the Vikings because Richardson's involvement in plays was helping other Vikings.

"Well, the one sack Danielle [Hunter] got, Sheldon [Richardson] actually knocked the quarterback off the spot and back up into Danielle, and he got a sack on that one," Zimmer explained. "Those are the kinds of things that happen."

Richardson also was an active tackler, along with Andrew Sendejo, when Minnesota stuffed Alfred Morris at the 1-yard line and Joseph punched the ball free. Harrison Smith recovered it at the 2.

Zimmer was asked Monday if Richardson had shifted from "preseason mode" to "regular-season mode" and said, "I guess so. But now it's on tape, and I know what he's going to look like and what he's supposed to look like."

"He played very, very well," Zimmer reiterated. "He was strong at the point of attack in the running game, he made a lot of tackles. He played real hard, pushed the pocket. There were two times that he took the guy with one hand and knocked him back. He played really, really well. We need him to continue to play like that."