Borthwick, capped 27 times, has not played for England since last season's Six Nations Championship, but he earned a recall in an extended training squad for the Twickenham appointment with tournament favourites France.
England locks Louis Deacon and Danny Grewcock endured a torrid time during the record 43-13 Six Nations loss to Ireland last Saturday, suggesting Borthwick might feature prominently in head coach Brian Ashton's plans.
But initial signs suggest he could struggle to be fit, with Bath head coach Steve Meehan admitting: "He is in quite a bit of discomfort. It is a rib injury, and he will have a scan later."
Neither Borthwick nor Grewcock could make little headway against a resilient Worcester outfit, who secured a first Premiership home win of the season through wing Thinus Delport's try double and 11 points from the boot of full-back Shane Drahm.
And Warriors rugby director John Brain was quick to acclaim the effort of his forwards in the set-piece exchanges.
Brain said: "I think John Wells turned up to watch Steve Borthwick, Danny Grewcock and Lee Mears, but he ended up watching Craig Gillies and some of our other forwards!
"Bath have a strong set-piece, and I thought the key to the game was that we managed to undermine them in those areas.
"We dismantled their lineout, which not many teams manage to do. We gave ourselves a good platform up front, although I was disappointed we took our foot off the pedal after scoring our second try."
Worcester's first home league win of the campaign cut the gap to four points on 11th-placed Northampton, and Brain added: "We have given ourselves an opportunity to get out of this mess.
"There is a four-point gap now, and it is possible for us to turn that around. We play Sale, who are struggling a little bit, next Friday, then we are at home against Newcastle the following Friday.
"I would have to say they are winnable games for Worcester - they are vital games for us."
Bath, without an away Premiership success since February last year, created tries for fly-half Chris Malone and substitute Shaun Berne, but could have few complaints after finishing second best against the Worcester forwards.
Meehan added: "I am bitterly disappointed. Our set-piece didn't function, and we gave away too many turnovers. You cannot expect to win games if that happens.
"Not winning away from home has started to annoy the hell out of us. It is inexplicable, really.
"We talked all week about attacking Worcester's defensive pattern, and we did that for 10 of the 80 minutes, then we played into their hands."