They will now focus their attentions on the semi-leg of their European Shield semi-final against Worcester, where there trail their Premiership rivals by nine points.
The Yorkshire side met favourites Bath in the Twickenham final and suffered a major setback when in-form Balshaw limped from the field after 25 minutes.
British Lion Balshaw had been struggling all week after tearing a quad muscle strained in training and his insistence in featuring in the Twickenham triumph could cost him a place in the Worcester clash.
"It felt OK in the warm-up but when I had a run and tried to kick on a bit, I just felt a bit of a pop," said the full-back .
"Obviously, there is a bit of worry there. I wasn't 100% really, but I desperately wanted to play."
Leeds coach Phil Davies will now sweat on the results of a scan to see how long he will lose his skipper for but it's doubtful Balshaw will make it back in time for Friday night's clash at the Sixways Stadium.