The Belgian's team endured a difficult time in Barcelona, dogged once again by dismal reliability issues affecting its Honda power-unit.
Over the course of two weeks, McLaren-Honda never succeeded in achieving more than eleven consecutive laps of the Circuit de Catalunya.
"It isn't easy for Stoffel, but it isn't all lost either," Villeneuve told Belgian broadcaster RTBF.
"The only thing left to do is to try and beat Fernando Alonso. It's still better to be in a team like McLaren than staying home doing nothing.
"He's a professional driver who doesn't have to bring money to the team, a rare occurrence these days. He should feel happy about that."
"He's also racing alongside a man of great talent, whom he can measure up to. How he will perform against Fernando Alonso will define his value... or not."
"If he was racing against another new young driver, beating him or not would not mean much."