The Grove based team had a horror 2013 season, but with a much improved package this year, Bottas has apparently outperformed his new teammate - the highly experienced former Ferrari driver Felipe Massa - so far.
But Venezuelan Maldonado said: "I don't think he (Bottas) is a very tough rival.
"I think Felipe has shown that he is superior to him but just more unlucky.
"I think you cannot always analyse just the result," the 2012 Spanish grand prix winner, who more recently has been the subject of social media ridicule for his own troubled 2014 campaign, is quoted by Brazil's Totalrace.
"In the first race Felipe was taken out; in another it took five minutes to change his tyres. It is a mistake to not look deeper than just the result," said Maldonado.
"For sure Bottas is a fast and professional driver and deserves to be in F1. But I don't believe he is faster than Felipe.
"Felipe has shown he is fast and consistent and very experienced, as he was at Ferrari and now at Williams, who have improved a lot since last year thanks to the Mercedes engine," he concluded.
Book discounted tickets and reservate your hotel room in our F1 Tickets Shop.