London Irish boss Brian Smith admits he is concerned by speculation linking prop Alex Corbisiero with a switch to Saints.
The loosehead prop is out of contract at Irish next summer and there has been speculation he could be set for a move to Franklin’s Gardens.
Saints look set to lose both first-choice props as Soane Tonga’uiha and Brian Mujati have been made big-money offers by Racing Metro.
Corbisiero, 24, could be seen as the man to fill the void left by Tonga’uiha, but Irish director of rugby Smith is keen to keep the England forward.
“First and foremost players are not allowed to negotiate with other clubs until January, so we would be very disappointed if Corbs and his agent Rob Burgess have shopped him to Northampton,” Smith told the Reading Evening Post.
“The agent could lose his licence if he has been shopping him around, while the player and club could be in for a big fine.
“We would be disappointed if that turns out to be the case.
“I imagine it is just hearsay, but we will not see Corbs until after the weekend so I can’t pour cold water on it because I don’t know.”
And Smith added: “We have made Alex a very robust offer. He is part of our senior playing group.
“It is concerning, but it is the time of year when there are these sort of rumours.”