"Dele gives us power and strength in our attack and is worth more to us than Forest could offer," said Johnson.
"There is a new contract on the table awaiting his signature and I hope he will sign it soon.
"We were poor in the first half, but it only took a look from me at half-time for the players to know they had to do better.
"We sorted a few things out and in the end could have had more goals."