The 25-year-old has been out with a foot injury for nearly a month but was back in first team training earlier this week.
“It is going to be tight, but sometimes tight is enough!” Tuchel stated at a pre-match press conferance when asked if Gundogan will play.
“We will wait and see how today’s session goes.
“He started [on Tuesday] with a low intensity. Today he will have the opportunity to train more intensively. Then we will look at how his foot copes.
“However, we also need to respect that fact that he was out for a while.”
Dortmund host Liverpool at the Signal Iduna Park, kick-off is at 20:05 (GTM).
Gundogan has been closely linked with Liverpool according to the Daily Star newspaper.
Liverpool will however, face competition from Manchester City whose sporting director Txiki Begiristain has already met with Gundogan’s uncle and agent Ilhan Gundogan regarding a summer deal.
Dortmund go into the game in great form having won 15 of their 17 games in 2016 – drawing the other two.