Yes, according to the wiki, Tank Bigsby suffered a core muscle injury during Week 4 that requires surgery. He's been placed on injured reserve and is expected to miss a minimum of 6 weeks (from the Saquon Barkley page, citing the Eagles' Oct 6 update).
This happened after he took over for Saquon Barkley (who hurt his hamstring in the same game). Bigsby handled 14 carries for 55 yards before his own injury surfaced.
The Mayo Media Network also noted on their YouTube channel that Bigsby has been put on IR, leaving Will Shipley as the last healthy Eagle in the backfield for Week 5.