Ellefson announced his retirement from the NFL on Thursday, Aaron Wilson of KPRC 2 Houston reports.
Ellefson re-signed with the Vikings on Wednesday, Craig Peters of the team's official site reports.
Ellefson will not receive an RFA tender from the Vikings, Chris Tomasson of the St. Paul Pioneer Press reports.
Minnesota placed Ellefson (groin) on injured reserve Wednesday.
Ellefson (groin) has been ruled out for Week 13 versus the Jets.
Ellefson (groin) was activated off of the injured reserve Wednesday.
Ellefson (groin) was designated to return from injured reserve Wednesday.
The Vikings placed Ellefson (groin) on injured reserve Saturday, Alec Lewis of The Athletic reports.
Ellefson (groin) has been ruled out for Sunday's contest against the Bears.
Ellefson had two receptions for 24 yards on two targets in Sunday's win over Detroit.