Shearer thinks the current Toon side can succeed.
He said: "When they drew Benfica, it did bring all those memories flooding back.
"But the first thing I thought was how lucky they were to have the second leg at St James'. That can be a big advantage.
"They've got a good chance. The additions made in January have made all the difference.
"I have no worries about them being relegated, though I did before all those signings. The squad's been strengthened with quality additions."