Everton fuelled by points penalty disappointment - director of football
The Merseyside club were docked points with immediate effect last week after being found to have breached profitability and sustainability rules (PSR) relating to losses.
The penalty sees Sean Dyche's side drop to second from bottom with four points, above only Burnley on goal difference, despite having claimed four wins from 12 league games this season.
In a statement on Everton's website, Thelwell said the club remained united and focused despite the penalty, adding that their resolve was "supplemented by the additional fuel of what we believe is a wholly disproportionate ruling".
"We are rallying in the face of a sporting sanction in the only way we can - and that is our focus and hard work in supporting the team in delivering to their fullest on the pitch," Thelwell said.
"We go into this weekend having secured six wins from our last nine outings in all competitions. The team has displayed a level of effort, camaraderie and bravery that is synonymous with this club in earning those victories. That spirit remains strong - unwavering."
Everton next face Manchester United at Goodison Park on Sunday.