The striker missed a penalty in Sunday's defeat to Sampdoria and there were rumours the Italy international could be dropped, only for the Giallorossi boss to swiftly deny them.
“Osvaldo will play if he is in shape; there is no doubt about that,” he told reporters.
“It has been a heavy week for him, one where a lot of untruths have been written.”
Roma sit in ninth place in Serie A ahead of the weekend and are on a run which has seen them pick up just two points from six matches, with coach Zdenek Zeman getting the sack on February 2.
And Andreazzoli has recognised the need to take one game at a time in a bid to turn around a rough patch of form.
He added: “The objective is to win the next game. We’ll look to get out of this situation by winning tomorrow and then the next one. We have to be realistic though as the situation is not an easy one.
“Juve are a really strong side, a team that I greatly admire so I have had to prepare for it like a maniac.”