Last season, Bishop scored 20 times in the league for Pompey and he has already scored five times this season in ten games.
However, on Saturday, Portsmouth managed to clinch a 2-1 victory over Wigan Athletic without Bishop registering his name on the scoresheet.
Whittingham pointed out that more Portsmouth players are getting into the opposition box and believes that it is a good sign that other Pompey players are contributing when Bishop is not scoring.
“They are getting more people into the box”, Whittingham said on BBC Radio Solent.
“Today for Lane’s goal, Robertson was in there, Lane was at the end of it and the other one was from a corner so you are going to have players in the box.
“It is nice that Bishop got some help up there and when he is not scoring goals, others are now contributing where at the beginning of the season and last year, if Bishop did not score, you were not quite sure where the goals were coming from.”
Portsmouth have managed to extend their unbeaten run in the league to 21 games and they suffered their last defeat back in March against Sheffield Wednesday.
