Mercedes team principal Toto Wolff conceded the team had 'let Valtteri Bottas down' after a sensor issue caused his W12 to enter a safety mode whilst hunting down Max Verstappen.
Bottas started the Portuguese Grand Prix on pole and led comfortably in the early stages before team-mate Lewis Hamilton conjured a stunning move around the outside of turn one on lap 20.
Keen to extend the opening stint of the race on medium tyres, Red Bull caught Mercedes with the undercut to relegate Bottas to third behind Verstappen.
Wolff said: "We lost the undercut, that was unfortunate, and then we let him down with the engine that went into a safety mode.
“All in all, like many times, it could have worked for Valtteri and we were pushing hard and will continue to support him and next time will see what he is capable of doing in Barcelona.”
Further explaining the problem, Wolff added: "That was unfortunate because he really caught up well to Max and then it kind of stabilised at 1.5 to 1.6 seconds but he had more to come at the end of the race.
"Then we made a switch change in order to override a sensor that was saying we are running too hot on the exhaust temperatures. We couldn't override it so the engine went into protection mode and it cost him five seconds."
Wolff used the Finn's pole lap as evidence he is still capable of taking the fight to Hamilton and Verstappen despite a difficult start to the year, although there is already a 37-point gap to the Briton.
“He will be on top form. He was on Saturday," said Wolff. "When you consider where he came from after Imola, that was a very write-off weekend and he put it on pole and had a very solid race, he led.
“It is clear when you are at the front just kicking a hole in the air and the car behind you has DRS, that is very difficult and the moment Lewis opened up a little bit of a gap, that was gone."
In the closing stages, Mercedes pitted Bottas in a bid to secure the point for the fastest lap. However, the team stopped three laps from the end, which gave Red Bull time to react.
Had Verstappen's time not been deleted for exceeding track limits, this error would have come at a cost.
Wolff quipped: “Yeah, we had a little bit of a stupid moment. It should have been the next lap but learn and move on.”