Ballack believes the transfer makes sense for Werner and for Chelsea.
The 24-year-old has been in superb form this season, netting 31 goals and providing 13 assists in all competitions.
“I think it's a good decision for both sides. For Timo, because he fits there, because the way [Chelsea] play football suits him," the former Germany midfielder explained to Sky.
“I think that in Chelsea he has decided on a club where he has a better chance of playing, which is very important to him.
“The team will be renewed, it will certainly be strengthened and a lot of money will be spent in Chelsea to knock again at the top.
“A good young team is being built there, which is very promising."