Terry Bullivant used to be a coach at Palace

Lewington's previous first-team coach Terry Burton left to become assistant manager at Championship rivals Cardiff in September.

"Losing Terry Burton could have been a real tricky one for us because he is one of the best coaches in the country," Lewington told BBC Sport.

"I needed to move quick and I was very lucky Terry Bullivant was available because is an excellent coach."

Lewington added: "Terry Bullivant has a different personality from Terry Burton.

"But Terry Bullivant has slotted in very easily, the lads have really enjoyed his sessions and I have worked with him before and so I trust him."

Watford are back in action this weekend after the international break.

And Lewington is hopeful of a positive result at Derby after defeat at Crewe in their last outing.

"Our last performance was the defeat at Crewe and ideally you would like to get that out of your system four or five days later," added Lewington.

"We knew where we went wrong 10 minutes after the game - we didn't close down hard enough and we did not work hard enough.

"It was a good reminder that if we take our foot on the pedals, no matter who it is against, we will come unstuck."