Ricciardo endured a tough start to the 2024 season, being outperformed by team-mate Yuki Tsunoda in the opening race while struggling to get comfortable aboard the VCARB01.
The Australian's difficulties dashed the momentum of him being considered for a 2025 Red Bull seat, but in recent races, he has been working his way back to competitiveness.
In China, following a requested chassis change, Ricciardo was vying for points until he was hit by Lance Stroll under a mid-race safety car.
In Miami, Ricciardo qualified and finished fourth in Saturday's sprint to score his first points of the year, employing a stout defence against intrinsically quicker cars over the 19-lap contest.
Team principal Mekies said that performance didn't come out of the blue as Ricciardo had been making improvements in recent races without a result to show for it.
"I'm sure it was a huge weight [off his shoulders] because the US is nearly his second home race," Mekies told Motorsport.com.
"He did it in style with an incredible defence to Carlos [Sainz] and the McLaren [of Oscar Piastri]. It was a fantastic moment for him.
"In fairness, we had seen signs of improvement before, but it was very difficult to explain it to the world.
"Saudi was a better performance than Bahrain, Australia was better than Saudi, Japan was better than Australia and China was better than Japan.
"It had been coming in many, many small steps and we think there is more steps we can do in the next few races to help suit the car better to him."
When asked if there was a definitive answer on why he struggled, Mekies said: "Let's just say that we identified stuff he was not happy with and took away quite a lot of the speed.
"We have tried to tick all the boxes to erase these limitations and there are a few more we would like to see ticked over the next few weekends.
"It was always planned to introduce a new chassis before race six. It was a nice box to tick on our issues with Daniel to make him more comfortable and he did better straight away in China and Miami.
"It's a big value for a team to be able to understand and analyse what is happening with the drivers and it's not always visible on the data.
"We are still trying to understand what it is that was disturbing him before, and it's a work in progress."
Ricciardo endured a much tougher main grand prix, being eliminated from Q1 in 18th and finishing in a train in 15th. According to Mekies, that swing of results shows how easy it is to be bumped out of a tight midfield pack if drivers or teams get the tiniest thing wrong.
"You have to nail every single aspect of the weekend at a top level. If we don't do it, we are out of Q1 straight away," he explained.
"We had a fantastic performance with Daniel in the sprint quali and in the sprint itself. And then in the main quali, we were a little bit out of the tyre window, a little bit of a mistake there, and suddenly you're out and that's the reality.
"That's what I like about racing. It's 10 or 12 cars fighting, but it's certainly a very intense pressure on the team."
