Dwelley (ankle) has been ruled out ahead of Sunday's game against the Seahawks, Matt Barrows of The Athletic reports.
Dwelley sustained a right high-ankle sprain in the 49ers' Week 13 win over the Eagles. He was unable to participate in practice all week and is set to miss his first game of the year. In Dwelley's absence, Brayden Willis is set to step into the No. 3 tight end role behind George Kittle and Charlie Woerner.