Townsend joined Newcastle from Tottenham earlier this week for a transfer fee reported by BBC Sport to be about £12 million.
“Newcastle need players who are going to come in and who are going to play at a consistent level every game,” said Nicol. “If there is one thing Townsend doesn’t do is comes in to the field and is consistent at a high level.
“He is either up there (gestures with his hand) or he is down there or he is say on his backside on the bench. So Newcastle are taking a gamble because of the potential that he has.”
Townsend has not played regularly for Tottenham since last season, but he has maintained his fitness over the past few months by playing with the Under-21 side.
The England international winger has pace and energy, and that will be important for Newcastle in the coming months.
The 24-year-old will also have a point to prove at St. James’ Park and show his doubters that he can fulfil his potential.
Newcastle are third from bottom in the Premier League table at the moment with 21 points from 23 matches, two points behind 17th-placed Norwich City.
Townsend scored two goals and created 13 chances in 17 Premier League appearances for Spurs last season.
The Englishman could feature in just three league matches this campaign, creating two chances in the process.