Oliveira netted Forest’s winner as they overcame Preston North End at the City Ground.
The Portuguese striker finished off a fine counter attack from close range to secure the three points for the Reds, and Freedman was encouraged by his performance.
“We’ve all got to be patient with Nelson. He’s a wonderful player who sometimes does the unexpected," the Scottish boss said. "We’ve got to remember that he’s a flair player and sometimes he’s going to give the ball away in certain areas.
“But I thought he showed a good goal threat tonight, took his goal well and showed good running off the ball.
“I thought Ryan Mendes and Nelson were right on the top of their game tonight.”
Oliveira did have to be withdrawn in the second half, after he picked up an injury.
Forest will be hoping that his fitness problem is not serious, as Oliveira has been the best scoring threat throughout the campaign so far.
The 24-year-old has netted nine goals in the Championship this season, with Matt Mills next in the club’s scoring charts after hitting the back of the net five times.
Forest’s win over Preston has pushed them up to 13th in the Championship table. The Reds’ next match comes against high flying Sheffield Wednesday at home on Saturday.