Sokolik joined Plymouth in January 2017
The 24-year-old was a free agent after leaving Southend United in December 2016.
The Czech, who represented his country at under-16 and ubder-17 level, started his career with Liverpool, where he had a loan spell with Southend in 2013/14, making ten appearances, before joining Yeovil Town in June 2014, making forty-five appearances for the Glovers.
He returned to Southend on loan in October 2014, but his spell was cut short by injury.
In the summer of 2016, he made the move to the Shrimpers on a more permanent basis, playing five times, before switching to Plymouth.
He left Home Park by mutual consent at the end of last month.