Defender Zanka felt that Brentford were not good enough in either penalty area against Crystal Palace.
Despite taking an early lead through Keane Lewis-Potter, the Bees were beaten 3-1 at Selhurst Park on Saturday.
“It’s disappointing, especially when looking back on the great start we made to the game. We started off on the right foot,” he said.
“But we weren’t good enough in either box today and that hurts.
“We all went into this game with the mindset that we had to bounce back. Thomas [Frank] decided to mix it up a bit and play three at the back and initially it looked like it was working.”
After one win in eight Premier League matches, Zanka stressed the need for resilience over the coming weeks.
“We go through rough patches every year, so it’s about how you get out of them,” he said.
“We had it the first year in the Prem when we lost five games, so we know how it is and we know how to get out of it.
“It’s up to us to dig deeper and make sure we get out of it as quickly as possible.”
Ivan Toney, who was responsible for 24 goal contributions (20G, 4A) last season, is available for Brentford’s next Premier League game against Nottingham Forest on 20 January.
Toney’s eight-month ban comes to an end on 16 January, and Zanka is looking forward to the striker’s return.
“Ivan’s one of our best players, if not the best player, so to have him back playing is huge,” he said.
“If he’s on the pitch, we know we have a guy who can score goals and hold the ball up and we can create from there.”