Ricciardo scored points for the second consecutive race, while team-mate Lando Norris recorded the team's first podium of the season.
Mixed conditions saw many drivers make mistakes, including Lewis Hamilton who found the barrier midway through the 63-lap affair.
“I'm also happy with how Daniel was battling through today,” Seidl said.
“It was not an easy race for him because he didn't feel that comfortable in the car compared to Lando all weekend to drive the car at the limit.
“We have seen today in these tricky conditions that a lot of people got it wrong and went off while trying to do too much.
“Daniel drove, in my opinion, a great race, and still scoring despite the struggles he's still having with our car at the moment, still scoring a very important P6 for us.”
Ricciardo had headed Norris in the opening laps, before being moved aside by the team to allow the Brit through.
It was a decision which ultimately set up the team's chance of a podium result.
“We have a clear agreement with both drivers and within the team that we will always make decisions that ensure that we maximise the result for the team,” Seidl explained.
“We let our drivers race feely but, let's say if we see that they run into each other on track, and if we judge it as one driver having a superior pace at that moment compared to the other driver, we make the decision to swap.”
Ricciardo has 14 points to his name and sits tied with Carlos Sainz for sixth in the drivers' championship, currently headed by Hamilton with Norris third on 27 points.
Formula 1 next heads to Portimao for the Portuguese Grand Prix on April 30-May 2.