Williams missed two-and-a-half days of testing in Barcelona because there FW42 car wasn't ready for action as teams look to collect data ahead of the new Formula 1 season.
Russell took to the track for the Grove-based side for the first time on Wednesday evening and then the Thursday afternoon.
The Formula 2 champion still has confidence his team, who finished bottom of the constructors' in 2018, will be able to react to the disastrous start to the season and bounce back.
"I think even myself, until you're involved in an F1 team, you do not understand how much work goes on just to get an F1 car on the track," Russell told Motorsport.com.
"I went around the factory and saw everybody in January, and I was amazed. I've been in an F1 team for two years now and I was amazed at how much effort goes in just to make the simplest of parts.
"We've seen it before, Force India missed the whole of 2015 testing and they finished fifth in the championship. And you don't get points for testing. Who knows what will happen?
"I think our job right here and now is to try and motivate everybody. Obviously the whole team is a bit frustrated and disappointed with how things turned out this week.
"But we still need to stay positive, and as I just mentioned before we've seen it in previous years where teams haven't even arrived at the first test and gone on to have a great year.
"It's not the end of the world. We score the points in the racing not in the testing, so we have to keep our heads held high, and make the most of the situation."