That 1-0 defeat means Gulls fans are nervously looking over their shoulders. They are now in 22nd spot, one above the drop zone by virtue of a superior goal difference to York's.
"We're not playing Gillingham every week," Knill said. "It wouldn't surprise me if we picked up nine points from the next three games.
"It doesn't matter what other teams do. It was an opportunity for us. Before the game, no-one gave us a hope, but we had a chance because we were committed and if we do that for the rest of the season, I think we will comfortably stay up.
"It's so important that everybody is with us. Next Saturday, we need the crowd behind us just like the supporters were.
"That enthuses the players, and helps them to go and play. It picks them up, it puts the opposition on the back foot and that's what we need for the next three games.
"It was always going to be a tough game. You can see why they're top of the league. They've got good players on the pitch and on the bench."