Robert Kubica suggested in Monaco that he feels Williams teammate George Russell is getting preferential treatment.
Amid much fanfare, the Pole returned to F1 from a long injury layoff in 2019, but it has been reigning Formula 2 champion Russell setting the pace.
Kubica, though, got a good start in Monaco and was running ahead of Russell when the struggling team called the young Briton into the pits first.
"I thought the driver in front has priority in the strategy?" Kubica asked his engineer over the radio.
The engineer replied that it would be discussed after the race.
Kubica's good run in Monaco was ended when he was hit by Antonio Giovinazzi, telling the Eleven Sports broadcaster: "What can I say?
"As is usual in Monaco, there was not much else going on. I gained two positions in the first corner and was then driving my rhythm.
"A lot of people said that I would not be able to drive here, so it was good to finish. Overall, the race was quite good, but the strategy was not the best. That's it," he added.