Per Joe Short of the Express, Witsel's agent spoke to Spanish TV channel Antenna 3 about the move:
At the start Axel was not convinced by Milan’s proposal, because he was looking for a club that played in the Champions League
However, the Rossoneri were very insistent and at the end the player said yes to their offer. The first hurdle has therefore been overcome.
Now they need to satisfy Zenit’s demands. Milan are prepared to spend £14.4 million, but the Russians are asking for £21.6 to £25 million.
However, while the clubs negotiate the 26-year-old's price, it's wholly possible Chelsea could swoop in and hijack the deal.
Speaking exclusively with Bleacher Report's Samindra Kunti in January, Witsel confessed his admiration for the Premier League. He said:
I want to play in one of the top clubs in Europe one day. It’s true that I like the Premier League, because it is one of the best leagues in the world, for me, together with Germany and Spain. It is a very good league; it is a crazy league. A lot of my colleagues play there, but we will see. I am still young, only 26. We’ll see in the future.
The central midfielder would add great depth to Chelsea's squad.
As Witsel is far more capable than the likes of John Obi Mikel, his presence would allow Jose Mourinho to afford a rest to Cesc Fabregas and Nemanja Matic once in a while.
The Belgian is an accomplished passer and patrols the centre of the pitch with power and bite.
Chelsea will need to act quickly if they are to prise him away from Milan, but if they do, they will have made an excellent signing.
Chelsea Could Be on the Verge of Signing Charles Aranguiz
According to Jamie Sanderson of Metro, the French media are reporting that the Blues have "agreed a deal" for Charles Aranguiz.
The midfielder recently starred in the Copa America for Chile, scoring twice and making an assist, as he helped the hosts to the trophy.
Football journalist Jonas Giaever welcomed the news and gave his verdict on the 26-year-old.
Sanderson's report indicates Aranguiz could cost around £16 million.
Though, like Witsel, he would not command a starting berth due to Fabregas and Matic's outstanding partnership in midfield. Aranguiz would provide Mourinho with a far better alternative than is currently available to him.
The Blues' desire to add depth to their squad is well-founded, as it is perhaps the only thing lacking in Mourinho's side.
Chelsea's pulling power and the prospect of playing in the Champions League will be a strong lure for both players, so there's a strong chance either Witsel or Aranguiz could be at Stamford Bridge next season.
If the Blues strengthen in midfield, expect Mikel to seek pastures new.