Panthers will be without influential Simon Lambert for the rest of the 2016 season.
It has now come to light that the Lincolnshire-based rider suffered cruciate ligament damage to his knee in the early July crash at the East of England Showground which also left him nursing a broken hand.
And confirmation that Lambert will not race again this year means club chiefs are now plotting a possible team revamp in a bid to keep Panthers in contention for honours.
Promoter Ged Rathbone said: “We have now received confirmation that Simon will be out for the season.
“His knee injury is considerably more serious than he first realised and he will face a long rehabilitation.
“It is not good news for him or for the club, but it does mean we can now make plans for the remainder of 2016.
“We’ve got to seriously look at the team and make some harsh decisions to try to make ourselves more competitive.
“We’re clearly not strong enough to win the league without current one to seven and that is something we are going to need to address.”
Lambert had starred during two months in a reserve berth but crashed in his first ride after climbing back into the main body of their team.
He clipped the machine of team-mate Nikolaj Busk Jakobsen and then slammed into the fence in the third heat of the second leg of Panthers’ Premier League KO Cup quarter-final exit at the hands of Somerset.
Lambert has been replaced initially by Ash Morris, whose short-term stint with the club is understood to last until the week commencing August 8.