The 35-year-old Barcelona forward missed the team's opening defeat to the Netherlands, spending time in a cryo-chamber to help his recovery, and goalkeeper Wojciech Szczesny suggested the forward would play some part in the game.
It is a must-win game for both sides after Poland lost to the Netherlands and France overcame Austria in their opening matches.
"The Austrians will not be happy that he is fit... I don't know if he's ready for 90 mins tomorrow, it's not for me to judge," Juventus goalkeeper Szczesny told a news conference Thursday.
"The fact he's on the pitch will add a lot of value to our team."
Poland coach Michal Probierz said he would decide his line-up after Poland's training session later Thursday, but said "all players" were available, including Lewandowski.
"There is a big difference if you have the best player in the world on the bench, and if he's available to play or not," continued the coach, keeping his cards close to his chest.
"We will make a decision later today. I'm waiting for the decision from our medical staff. I hope the decision is positive and I hope I will select him tomorrow."
Former Bayern Munich striker Lewandowski is Poland's all-time top goalscorer with 81 goals.
'Best of all time'
Adam Buksa stepped in against the Netherlands and scored with a header from a corner before the Dutch fought back to win.
"Robert has been our best player for many years now and in my opinion he's the best Polish player ever, of all time," said Szczesny.
"Regardless of how well others play, because Buksa played a very good match, and scored against the Netherlands, the fact is that Robert Lewandowski will change our overall approach and our opponents' approach as well.
"It's natural that his presence on the pitch can only help us."
Earlier Austria said they were anticipating Lewandowski would feature at Berlin's Olympiastadion.
"We expect that 'Lewa' will be playing tomorrow... but it doesn't really change our way of playing a lot," coach Ralf Rangnick said.
"Lewandowski is the key player for Poland and everyone tries to pass to him. I think he'll be playing tomorrow."
Austria midfielder Marcel Sabitzer played with Lewandowski at Bayern Munich.
"I had the joy to play with him for a year so I know his qualities, he's an exceptional player," said Sabitzer.
"The tactics won't change for us. You can't give him space around the box... because he can score from any position."
Defeat for either side at the Olympiastadion would leave them on the brink of elimination.
"The importance of the match is clear," added former Manchester United interim boss Rangnick.
"The team that wins tomorrow has a good chance of going through so it's a match you have to win."