The 23-year-old tested positive to a substance that was allegedly on the AFL's banned substance list late last month.
He and the club have been awaiting the return of his 'B' sample.
The Saints informed their members via email on Tuesday night before releasing a statement on their website that said Saad had contacted the AFL to begin a provisional suspension.
However, they stressed this was not an admission of guilt or wrongdoing.
"The matter will be determined before the AFL tribunal at a date to be fixed," the Saints said.
"Ahmed will not be available for selection for the remaining two matches of the AFL home and away season and will continue to co-operate with the AFL and ASADA as necessary throughout this process.
"The club and AFL Players' Association will continue to provide appropriate support to the extent allowed under the code."
The Saints maintain Saad inadvertently ingested the substance that is believed to be on the anti-doping list.
He played against the Brisbane Lions the weekend after the positive return of his 'A' sample; a move that was defended by former Australian Sports Anti-Doping Authority boss Richard Ings at the time.
"Every sport and every government that has adopted the WADA code – over 200 governments and over 100 sports – apply exactly the same rule as the AFL applied on the weekend," Ings told AFL.com.au.
"The benefit of the doubt is given to the player and they are allowed to play until an anti-doping tribunal decides to impose a sanction against them.
"A positive test for a specified substance might attract a ban of weeks to a couple of months, depending on the circumstances.
"So if you provisionally suspend someone, they may actually be provisionally suspended longer than the actual ban would have been."
If Saad's 'B' sample is positive, he will be issued with an infraction notice that will lead to a tribunal hearing.
Saad has missed the past two games because of a quad injury.
The Saints said both they and the AFLPA remained "bound by confidentiality" under the League's anti-doping code and would not comment further at this time.
Any sanction could range from a warning to a two-year ban, depending on the degree of fault and care taken by the young Saint.
In a previous statement, Saad said he was "surprised and extremely disappointed to find himself in this position".