Speaking after the club's 2-1 win against Bristol City on Tuesday night, the Belgian worldwide said: "He's a very good player".
There is much speculation surrounding these reports, however, with the Evening Standard's James Olley tweeting that Arsene Wenger has claimed that the club has had "no contact" with Manchester City over the sale of Sanchez.
Sanchez looks increasingly likely to leave the Emirates before the January window closes, with Manchester City ramping up their efforts to sign him after Gabriel Jesus picked up an injury.
Sanchez, 29, is in his final year of his Arsenal contract, and will be a free agent at the end of the season.
'When he comes he will add something to the team, ' said the Belgium ace.
"We are in a good period already, the whole season". Everybody is doing a good job.
The North-West outfit are believed to be keen to tie De Bruyne down to a new deal, but at the moment there has been no movement. However, they chose to pursue the Chilean after striker Gabriel Jesus suffered a knee ligament injury that will keep him out of action for at least six weeks.
The Belgian said: "We have five days, that will be good". It will be nice to have five days and then nearly a week before Newcastle to get a little bit of recovery. We don't have to take care about that anyway.
"They will have a very strong team, they want to be there for the Champions League, but we just try to do the things we do good and then we will see what happens".
Arsenal don't have to sell - they can say: "We've got this far, we'll see it out".