The move follows a series of disappointing results by the Polish team, who placed 7th-8th at cs_summit 3, Toyota Master Bangkok and SuperNova CS:GO Malta to enter 2019 outside the top 30 in the ranking - just three months after sitting in 16th place in the table.
The failure to qualify for the Europe Minor, which will be held in Katowice, proved to be the final straw for Kinguin, forcing the team to undergo their first line-up change since TaZ took the reins, in March.
In a statement, the Polish veteran explained that reatz, who averaged a 1.06 rating on LAN with Kinguin, did not fit in with the team's style of play, adding that he will not be rushed into making a decision on a replacement.
"The results that our team got last year were not what we were hoping for," TaZ told HLTV.org. "We had some good moments and some bad moments.
"Still, our target is to compete at the highest level, and we had to make a hard decision. We decided to bench Pawel and see if we can find a player that fits our team better.
"I believe that Reatz evolved in 2018 as a player and as a person, and I hope he will get the chance to prove his worth in the future.
"We will take time to find our new fifth player. Thank you guys for understanding and supporting us, and I hope that this year our fans will have more reasons to be happy!"
Kinguin currently only have one tournament lined up, the ESL Pro League Season 9, which will kick off in April. TaZ's troops qualified for the prestigious league after beating fellow Polish side Virtus.pro at the relegation tournament, held in Dallas.
Paweł "reatz" Jańczak (benched)