And the international players' union is also demanding to know why the game's governing body did not include a plan for 'serious treatment' for the striker following his third biting offence in four years.
The union said the player's 'right to work' was also being infringed while Suarez and the Uruguay FA are appealing against the sanctions, which include a nine-match international suspension.
In a statement FIPro said: "This is a very serious matter, as reflected by the sanctions imposed by FIFA's disciplinary committee.
"The sanction will be reviewed and FIFA will have to focus especially on the accumulation of sanctions including a four-month ban from all football activity.
"The fact that Suarez is prohibited from working for a long period must be addressed as it directly infringes his right to work. Also the fact that Liverpool FC is affected needs to be an important issue.
"Luis Suarez should receive all the support he needs to deal with any off-field issues he may be experiencing at this time. This means that the focus should be on the rehabilitation and serious treatment of the player.
"FIFPro believes that treatment must be a part of any sanction. Luis Suarez deserves all the support he needs including legal support in the appeal case in order to achieve a reduction of the sanctions."
The player's lawyer Alejandro Balbi, meanwhile, told Spanish radio station Cadena Cope: "The ban is absolutely disproportionate considering what Luis did.
"Julio Grondona, vice-president of FIFA, told me that he had never seen such a serious ban handed to a player.
"This is so grotesque and absurd that the CAS (Court of Arbitration for Sport) will have to revoke this unjust ruling.
"Unjust not just due to the number of games given, which is already incredible, illogical and arbitrary, but also the issue of not being able to be allowed to have any relationship with football in 120 days, and then there's the fine.
"All that was missing was life imprisonment."