The 49ers claimed Fields off waivers from the Texans on Wednesday.
Fields was waived by the Texans on Tuesday, Ian Rapoport of NFL Network reports.
The Texans claimed Fields off waivers Thursday.
The Vikings waived Fields on Wednesday.
Fields (chest) was activated from injured reserve Tuesday.
Fields (chest) was designated to return from injured reserve Friday.
The Vikings have placed Fields (chest) in injured reserve, Ben Goessling of the Minneapolis Star Tribune reports.
Fields suffered a "pinhole puncture" of his lung during Sunday's 28-22 win over the Packers, Andrew Krammer of the Minneapolis Star Tribune reports.
Fields suffered an undisclosed injury during Sunday's win over the Packers, Tom Pelissero of NFL Network reports.
Fields was promoted from the Vikings' practice squad Monday, Aaron Wilson of the Houston Chronicle reports.