After a patchy start to the World Rally Championship season, Neuville has come good in recent events, finishing well inside the points on the last four rounds.
In an effort to ready the 24-year-old Belgian for the fastest WRC round of them all, he will head to Estonia on July 20-21, where he will face fellow WRC regulars such as Mads Ostberg and possibly local hero Ott Tanak.
Benoit Nogier, director of Citroen Racing Technologies, said: "From Sebastien Loeb to Kimi Raikkonen, Citroen Racing has entered its drivers in additional rallies to those in the WRC to help them prepare for the specific challenges of the terrains in question.
"As replacing a test session by taking part in this rally doesn't result in extra cost we felt that Rally Estonia was the best possible training for Thierry."
Neuville said driving over Estonia's high-speed crests would help him no end ahead of Rally Finland, which follows a fortnight later.
"With its crests and high-speed blind corners, Finland is like no other rally," Neuville said.
"In New Zealand we showed that we could run at high speeds without making any mistakes. I feel that I'm improving race after race, but I mustn't relax and I must keep on working.
"It's a great help to take part in a similar rally that will give us an idea of what to expect in Finland.
"We can work on all the following points: discover new stage in racing conditions, refine my note-taking system and optimise the car's setup, especially as the rally has over 160km of special stages."