Howard is set to spend the next month on the sidelines after the setback and is set to miss the upcoming games against Brive, Connacht, Harlequins and Sale before retuning to contention towards the end of next month.
The Sixways side have seen David Denton and Will Spencer come back from injury in recent weeks while Francois Hougaard (adductor), wing Bryce Heem (quad) and prop Simon Kerrod (adductor) should also be back, the club say, for the October 28 game against Quins.
Further down the line, versatile back Ryan Mills (quad) and Tom Heathcote (concussion) are scheduled to back in three weeks' time and head coach Carl Hogg admits having more options when players are fit again can only be good for the club.
He said: "We have got a clutch of players that are starting to create competition which is great for us. We did have one or two dinks at the start of the season but some of the players who had longer term injuries are starting to come back into the fold."