"Everyone was talking about this so it was important for him and for us that he scored," said the Reds boss.
"Maybe now people will talk about his first goal in the Premier League but at least he has now got his first in all competitions.
"A striker is always looking to score goals and he will now be hoping to get his first in the league so he can look to get lots more in the future. It was very important and is one step forward.
"The crowd here are very clever and they know a good player when they see one. Robbie has been a very good player in the Premier League with Tottenham and they knew it would just be a question of time."