Taqele Naiyaravoro will miss Saints' home Premiership Rugby Cup clash with Saracens on Sunday after being given a one-week ban.
Naiyaravoro was sent off for two yellow card offences during the defeat to Wasps at Franklin's Gardens last Saturday.
The powerhouse wing was deemed to have deliberately tripped an opponent during the first half and put in a high tackle on Owain James late on.
The second incident resulted in a penalty try, which ultimately earned Wasps a 36-32 win.
And Naiyaravoro's frustration doubled on Tuesday evening as he was given a suspension that will rule him out of this weekend's repeat of last season's Premiership Rugby Cup final.
Independent disciplinary panel chair Dr Julian Morris said: “The sanction applicable for the offence of receiving two foul play yellow cards is one week.
“There are no aggravating features and whilst the player would normally be entitled to mitigation for a guilty plea, remorse and a clear record because the entry point is a week no reduction can be applied.”
The case was heard on the papers only in the absence of Naiyaravoro by agreement with Saints.
Naiyaravoro will be free to play against Leicester Tigers at Welford Road on Saturday, October 12.