On October 1, users will no longer be able to access the online features of the aforementioned titles, as well as PSP racer Motorstorm: Arctic Edge.
Prior to this, PSP card game The Eye of Judgment Legends will also be decommissioned, losing its online capabilities on August 31.
Released in 2008, Motorstorm: Pacific Rift takes place in the jungle, on beaches and other tropical locations.
It was followed by last year's Motorstorm Apocalypse, which swapped the natural environment for an urban setting.
It is currently available as a free download for PlayStation Plus subscribers.
> Read Digital Spy's Motorstorm Apocalypse review
Watch a trailer for Motorstorm Apocalypse below: