Quintana, a winner of the 2014 Giro d'Italia and last year's Vuelta a España, has been frustrated in his efforts to win the Tour de France, finishing second and third in the last two editions both won by Chris Froome.
He will again be a major rival of Team Sky's Froome and Australian Richie Porte (BMC) when this year's race starts in Dusseldorf on July 1, but LeMond is not convinced by the 27-year-old's ability to mount the attacks needed to ruffle Froome's feathers.
SBS will broadcast all stages of the 1-23 July Tour de France.
"I would love to see Quintana win but he lacks the ability to attack and his time trial needs to be improved," LeMond said.
"He is too steady and needs some explosiveness to be able to drop people."
Quintana will lead a powerful Movistar team that also includes veteran Alejandro Valverde.
He had targeted a Giro d'Italia and Tour de France double this year but lost the Giro to Sunweb's Tom Dumoulin on the final day's time trial despite holding a 53-second lead.
LeMond believes Quintana will be physically ready for the Tour de France but says the psychological effects of losing such a tight battle could have an impact.
"Recovering from the Giro is psychological. That's the main thing," said LeMond, who won the Tour in 1986, 1989 and 1990.
"Physically your body recovers but if you've had a battle like Quintana had in the Giro, that can tough. But racing is better than training and if you do a three-week Tour and do the right recovery you should be in even better shape at the Tour."
LeMond also believes Spain's former winner Alberto Contador (Trek-Segafredo) will be dangerous after skipping the Giro.
"I would not be surprised if Contador was on top of his game. I think he tried to pull off too much last year with the Giro so wouldn't be surprised if he was right there," he said.
"He didn't have much help last year and had some bad luck and that's all it takes to throw you off."
Movistar long list for the Tour de France
Nairo Quintana, Alejandro Valverde, Andrey Amador, Daniele Bennati, Carlos Betancur, Jonathan Castroviejo, Alex Dowsett, Imanol Erviti, Rubén Fernández, Jesús Herrada, Dani Moreno, Nelson Oliveira, José Joaquín Rojas and Jasha Sütterlin.