Transfer expert Fabrizio Romano has confirmed a meeting was held earlier this month between United representatives and Guimaraes' agent and his partners.
United enjoy a good relationship with the agent, though nothing has been tabled nor agreed.
Instead, United will keep a watching brief on Guimaraes' situation before choosing whether to make a formal move closer to the end of the season
On the speculation, Toon manager Eddie Howe said last week: “Is it a problem for us? I don’t necessarily think it is a problem for us. But it is unwanted news, I suppose, is the best way to put it. You don’t want the players distracted. I don’t know how much they will absorb that.
“For me, it is not the time to think about it. In the summer, you can understand those stories a little bit more because the transfer window is open.
“To say our captain is in discussions with another club is totally disrespectful to Bruno more than anything else, he is totally committed here.”
Howe added: “I’m not going to be impolite, as this isn’t the forum for that, but for me, it is just a nonsense story.
“To say our captain is in discussions with another club is totally disrespectful to Bruno more than anything else, he is totally committed here.
“Bruno’s our captain, he’s fully committed, he’s injured at the moment, his only focus is coming back to fitness.”