"Gareth has been working hard to get back and to play with the side and, after his three months out from injury, he's come back and was very excited about playing again", the Frenchman told a pre-match news conference.
The Welshman had to be withdrawn early in the first-leg in Munich, which Real won 2-1, after experiencing muscle tightness in his right leg and has not recovered in time to feature in the reverse fixture at the Santiago Bernabeu Stadium.
The Bayern players landed in Spain convinced they can overturn their first-leg deficit, with playmaker Thiago Alcántara tweeting: "Never give up".
By contrast, Bayern welcome back their main man in Lewandowski, who has scored 38 times in 40 appearances this season, from a shoulder injury. So we will prepare well for the game, as we did for the first leg.
Isco stood out with two goals including a last-gasp victor in Saturday's game, but he has been used sparingly in Europe this season, getting just 77 minutes in total across Madrid's nine Champions League games to date. "We will need to play with intensity, with courage, with personality". We know Lewandowski is a real No. 9, the player he is. "They're all ready to play and that's the most important thing for me", he said. We don't want to risk anything with him but he should be ready in a few days.
Bayern has only managed two wins in 12 matches against Madrid at the Bernabeu.
Sunday's match between the fierce rivals will likely prove crucial in the title race, with the teams occupying first and second place in the Spanish league table.More news: These Rangers Hab to learn how to win playoff games at Garden
Real last kept a clean sheet against minnows Alaves on April 2 and have not looked solid at the back all season.
Champions League football returns to the Bernabéu tomorrow!
The Madrid side, who lead LaLiga by three points, could pay a high price for any similar slip-ups against Bayern, particularly with Lewandowski lurking.
Bayern had been the dominant home team in the Champions League until last week's loss ended its run of 16 consecutive home wins.
"Everything changes with him on the pitch."Two of the most decorated careers in the history of the Champions League could come to an end at the Bernabeu with Lahm and Xabi Alonso set to retire at the end of the season". "The first leg is already over".
The Portuguese scored twice in Munich to become the first player ever to make it to 100 club goals in UEFA competitions and, with 97 in the Champions League, he is also the leading scorer in the continental competition - three ahead of Barcelona's Lionel Messi.