Motherwell have rejected "significant" bids for defender Shaun Hutchinson and midfielder Nicky Law.
The Fir Park club say an English Championship club made an offer for Hutchinson, while a League One side have targeted Law.
Motherwell manager Stuart McCall said: "We understand every player at this club has a value.
"We also need to ensure we protect our interests by getting the right price for our talent."
Motherwell have lost several key players from the side which finished third in the Scottish Premier League last season, including Steve Jennings, Tim Clancy and captain Stephen Craigan who retired in the close season.
"Rejecting both offers, which were significant in Motherwell terms, is also a sign of intent from the club's board that they are not prepared to accept any bid that comes our way," said McCall.
"Unless a vastly-improved offer comes in then it is business as usual."
Newcastle-born Hutchinson, 21, has become Motherwell's first-choice centre-back under McCall after making his debut in 2009. He was previously the subject of an offer from Watford.
"Shaun has been terrific for us since I arrived at the club and has been a virtual ever-present in that time," said McCall.
"He has all the raw materials you would want from a centre-back - he's young, big and powerful and the experience of playing in the Europa League and Champions League is standing him in good stead.
"He is already a top player. I would say he's one of the hottest young talents in the SPL, and we are certain he'll mature into an even better defender as his experience grows. That's why any offer for him needs to be realistic."
Law, 24, signed a two-year contract when he joined from Rotherham last summer, and has proved a big hit with the Motherwell support.
"Nicky has been the cornerstone of a lot of success going forward over the last 12 months and is vital to us," added McCall.
"His contribution from midfield was key in qualifying for Europe last term and any offer for him would have to reflect his contribution to our side."