Spencer travels with his team-mates to league leaders Leicester on Saturday, knowing they could be overhauled by bottom club Worcester, who are just three points adrift.
But former All Blacks fly-half Spencer has moved to pledge his future at Franklin's Gardens by serving out the remaining year of his contract.
Spencer said: "I would like to say again that I have not been to Agen and that I am spending my future with Northampton.
"That's all I have to say on the matter, as I am more than happy to spend my last season with the Saints. I have loved my time here.
"The rugby is not going great at the moment, but I am remaining positive. Although we are in a hole, we believe we can get ourselves out of it.
"We have got to keep fighting on. The guys are trying hard, and it is frustrating because the results are not going our way.
"We are just lacking a bit of confidence. But we have got another eight games to go, and our focus is now on Leicester."
Northampton will tackle a Leicester side weakened by RBS 6 Nation Championship calls, but an emphatic home defeat against Harlequins last weekend suggests they are short on confidence in the quest to preserve their Premiership status.