Cristiano, who was rested for Juventus' 3-1 win against Atalanta on Saturday, trained with the rest of the squad on Sunday and trained normally again on Monday.
The Portuguese, who has only scored 6 goals so far this season, is looking to assert himself against Atlético who he has scored 25 goals against in 33 games, and who he scored tremendous a hat-trick against in the last 16 2nd leg last year.
The Italian Federico Bernadeschi also participated in the session but is a doubt for the match because of a thorax problem, and so is Matthijs De Ligt who has a shoulder issue suffered in the match against Atalanta.
On the other hand, Sarri will not be able to count on the Brazilian Douglas Costa, who finished the last league match with a right thigh injury that will put him out for around 15 days, according to Juventus.
The training session took place under the sun and it was about 14 degrees, good conditions that are also expected this Tuesday at 21:00 local time (20:00 GMT).
In fact, the Juve star confirmed on his Twitter account that "he is back" with a brief message. The post was also accompanied with 4 photos from the training, and he is expected to be 100% for the match against Atlético.