Sky Sports pundit and former Formula 1 driver Karun Chandhok believes Mercedes should be "concerned" by its latest upgrade package, warning that the new aerodynamic parts have failed to deliver the desired jump in performance.

Despite Kimi Antonelli closing in on his maiden drivers' championship title, Mercedes' form has plateaued in recent races. As Red Bull's Max Verstappen won the last two grands prix in Malaysia and Singapore, the Brackley outfit struggled to unlock pace from its updated W17.

Speaking on the Sky Sports F1 Show, Chandhok claimed the Singapore Grand Prix was not an "overwhelmingly positive" weekend for Mercedes. Antonelli finished third in the grand prix, while Russell, who started 19th due to grid penalties for power unit component changes, finished ninth. 

The Italian driver was running in the upgraded machinery at the Marina Bay Street Circuit, while Russell was using the previous specification. Although Antonelli outperformed his team-mate, Chandhok claimed the improvement in performance was not enough.

"I don't think it was an overwhelmingly positive weekend for them in that respect, if I'm honest. On the Friday, the downgraded car was quicker with George," the former driver explained.

Andrea Kimi Antonelli, Mercedes

Photo by: Simon Galloway / LAT Images via Getty Images

"When we got into the main qualifying, George was slightly on the back foot, obviously after the crash in the sprint. He said he was just trying to get a safe run through quali and do a sensible job. He wasn't that far off Kimi, to be honest.

"So, has the aero upgrade delivered a big chunk of performance? I think you'd have to say probably not, not in Malaysia nor in Singapore. So, I think they'll be a bit concerned."

Antonelli currently leads the drivers' standings with 340 points. Russell follows in second with 238 points, and Ferrari's Lewis Hamilton sits third with 229 points. As a result, Mercedes also leads the constructors' championship with 578 points. Ferrari is second with 444 points and McLaren is third with 339 points.