Hadden is under pressure to deliver a win at Twickenham
Frank Hadden's future as Scotland head coach will not be decided until the end of April, Scottish Rugby Union chief executive Gordon McKie has revealed.
Defeat to England would see Hadden fail to meet the SRU's minimum target of two Six Nations victories per season.
But McKie insists a 40% success rate is only one factor the SRU will consider.
"Speculation that this is Frank's last game is somewhat premature," said McKie. "The review can take anywhere between two and four weeks."
Former Edinburgh coach Hadden was given the Scotland job in September 2005 and enjoyed success in his first Six Nations, with three victories.
However, the 2007 and 2008 campaigns were disappointing, yielding just one victory from five outings each time.
"I will carry out a review with coaches, selected players and others on the periphery of the national team and reach our conclusion and share it with the board," added McKie.
"We review the performance of the national team after every series be it World Cup, autumn Tests or Six Nations."
We're planning something in the summer. That's what I'll carry on doing until told otherwise
McKie insisted he had no regrets at setting a minimum victory target when the SRU's five-year strategic plan was announced in 2007.
He added: "We will take into account all factors including how unlucky we were, frustration of dropping a ball and losing the game. How competitive were we? World rankings. Do we believe the future is rosy?"
On Scotland's latest displays, McKie said: "Without making excuses, I think we have been unlucky. Against Ireland, we lost one line-out and we lose the game. Overall, the performance against Ireland was a good one.
"If we win at Twickenham, that will be the first time we have won in 26 years which would be a good end."
When asked if he felt under any additional pressure ahead of the clash with England, Hadden told BBC Scotland: "Definitely not.
"It's just the same pressure every week. It's very tough winning international rugby matches for Scotland but that's what we're trying to do and I think we've got a very good chance this weekend. We can't wait for it.
"At the moment, we're planning something in the summer. That's exactly what I'm doing, that's what I'm paid to do and that's what I'll carry on doing until told otherwise."