The decision to loan Stern John to Bristol City before Saturday's 3-0 loss at Swansea led to a chorus of boos from Saints away fans during the match.
Manager Jan Poortvliet has attempted to explain the striker's departure, blaming the decision on a need to free the club from John's wages.
"The actual reason you all know," Poortvliet told the Daily Echo. "We talked at the beginning of the season of the wage bill and that's still a problem."
That is unlikely to satisfy Saints fans who have 20-year-old David McGoldrick and midfielder Andrew Surman tied as the club's top scorer with three goals each.
With few other options, McGoldrick and Bradley Wright-Phillips could continue in attack when the Saints host 17th-placed Coventry on Tuesday evening.
Stern John left Saints to reduce wage bill
Jan Poortvliet is hoping the next Saints transfers will be players coming in rather than going out after the massive disappointment of Stern John’s departure last week.
Following an angry reaction to the move by fans, the Saints head coach admitted he wanted John to stay and that the striker did not want to leave.
But, with Poortvliet not able to guarantee the striker would play every week, a financial decision was taken by the club’s hierarchy to let the Trinidad & Tobago international move to Bristol City on loan until January.
Saints looked desperately short of firepower in their 3-0 defeat to Swansea and a vocal section of the 1,000-strong away support made their feelings clear.
They chanted John’s name and ‘we want Rupert out,’ as they blame Rupert Lowe for the striker’s departure.
When asked directly why John left against his and the Poortvliet's wishes, the head coach said: “The actual reason you all know. We talked at the beginning of the season of the wage bill and that’s still a problem."