Ferguson felt the club's top scorer was unlucky not to be credited with the winner at Sunderland at the weekend, as Titus Bramble was ruled to have conceded an own goal after the Dutchman's shot ricocheted off his knee.
Van Persie, following his cameo substitute appearance in the FA Cup exit at Chelsea, has now gone nine games without scoring with his last goal coming in the home win over Everton in February.
However, the manager rejected any suggestions that the 30-year-old needed a break at this stage of the campaign with eight games to go.
"Robin doesn't need a rest, that's for sure," Ferguson said. "He's a strong lad with a great physique.
"It's disappointing he wasn't awarded the goal at Sunderland - I can understand that because it took a wicked deflection. His shot was fantastic - it was hit with such venom that it's not surprising it took a deflection.
"But his ability to manoeuvre his position at that point was excellent. The goals will come. All strikers have little dry spells - you always hope it ends quickly. It's just part of being a striker."
The forward did net the late winner in the corresponding derby fixture at the Etihad Stadium earlier in the campaign and Ferguson said he could draw on his own experience as a player in Scotland to offer advice when it comes to taking chances.
"I didn't have dry spells (as a striker)!" Ferguson joked. "I remember I had a spell at the start of one season when I had a little knee injury and didn't score until October and I still ended up with 30-odd goals!
"You have to get through that period and not lose your faith and belief in yourself. My dad always used to say make sure you batter the ball when you're in there, don't tap it or try and sidefoot the ball in the net, batter it!
"That's what I always tell strikers - when you get in the position make sure you hit it. If the goalkeeper saves it, you can say 'what a great save'. But if you try to sidefoot it in and the keeper just catches it easily, you'll get criticised for that.
"It's just being sensible and realistic. Robin's shot last week could have come off any defender because it was hit so well and that's the right thing to do."