The 2019 world champion has been struggling to unlock the set-up sweet spot in his Puma this season which has hampered the Estonian's pace outright pace.
In Portugal last month, Tanak identified that the car's suspension was an area earmarked for improvement. Since the event, M-Sport's suspension supplier Reiger has provided upgraded components which were run for the first time during the team's pre-event test last week.
While Tanak is unsure if the new developments had solved all of his issues, the 35-year-old is confident his Puma has made a step forward.
"I really needed this test. Reiger brought some updates and it worked quite okay," Tanak told Motorsport.com.
"We have made some steps since Mexico but in Portugal, the biggest struggle was with suspension and they have come up with some new solutions, so we have definitely made the first step and it felt better [in the test].
"It is a bit early to say if we are completely there. We have definitely improved."
The Puma impressed on Sardinia's rough gravel roads last year when Craig Breen finished second, while Pierre-Louis Loubet scored a career-best fourth.
"Everything that happened last year is last year," added Tanak. "We are now one year forward and everything has changed. In motorsport nobody stands still so let's see."
Hyundai opts for suspension gamble
Hyundai will join M-Sport in trialling something new in Sardinia which team principal Cyril Abiteboul has labelled as "measured gambling".
The Korean marque conducted a test with Esapekka Lappi at the squad's Finland test base where an experimental suspension set-up was tested which the Finn will try on Friday.
"We did two days of testing. I think we managed to do something for here which I will try on Friday," Lappi told Motorsport.com.
"I feel in Portugal we were missing a bit of pace compared to Toyota so I wanted to try something to make it better. If it doesn't work then we can go back to the logical set-up which we know. It is risky but it is worth a try."
Lappi's decision to experiment with his i20 N has been praised by Abiteboul as the team looks to score its first win of the season in Sardinia, a venue where the carmaker has won five times.
"We have been testing and we have had quite a successful couple of test campaigns, one before Portugal and one before here," Abiteboul told Motorsport.com.
"The one before Portugal led to Esapekka bringing something different, and that was maybe visible as he was more competitive. It was a step that Thierry elected not to take and there is a similar step coming this weekend which Esapekka is going to run.
"Esapekka is really keen on pushing the team and the boundary of the car. He is not shy in testing new things in rally conditions. I like to have someone driving the team from a technology perspective.
"It is measured gambling, we are not doing anything that is silly."
Thierry Neuville will also opt for a similar set-up after struggling with the damper configuration he elected to run in Portugal.
