do not underestimate rumour because it is very likely to be true and i'm pretty sure that between all those rumour above me there will be at least one who became true and i was found the new one currently if Alexis Sanchez leaving Arsenal on January and might be Arsenal will buy Marco Reus from Dortmund as the replacement and some people believe that he would went to England this winter
Now that's not ever happening knowing how stingy Wenger is during transfer windows. And I don't think Dortmund is willing to let go of him just yet. At least not this January, so if a club is truly interested in him, then they should pay for a premium to get his services. I'm almost 100% sure Wenger will not sign him because of the steep price tag.
Sanchez is no longer a young player and Im not sure why would he be leaving the club when they are doing very good on their side. He got a pretty decent wage and got the opportunity to be on the first team, as a player of his age that is what left that he could wish for anymore