Inter need to overturn a 2-0 deficit at Anfield to reach the Champions League quarterfinals.
Cassano said on Bobo TV: "Complicated, very complicated, because in the first leg a heavy but undeserved result arrived.
"In those games there must be decisive players who transform at every goal chance.
"Sanchez will be a starter for me, you have to put him in such decisive games. It is right to trust Lautaro, but very little space for Sanchez who should not be treated like this, in my opinion, but with more respect."