This game seems good for Real Madrid. Salzburg is not doing well right now having only won one game out of six which makes it hard for them to be in top 24. If Real Madrid wins they might move into top 15 which would help them get spot in playoffs for next round. At same time Brest is doing better than expected this season and is currently in top 8. Their next game against Shakhtar Donetsk another team that not doing well is chance for Brest to keep doing well. But Real Madrid has a lot of experience and skill which will probably help them win and move on to next round.
Real Madrid are facing a lot of challenges in the champion league this season, because their performances has been very poorly right from the beginning of this season, I don’t think Real Madrid can able met up in the champions league leagues this season.
Because they’ve already loser 5 matches out of the six, that means they still have a lot to do before the league should come to an end.
Losing 5x?

The reality is that Real Madrid have 3 wins and 3 losses, and to be able to advance to the play off round is enough ranked in the top 24, not shoud in the top 15. But the point is, Real Madrid still has a very good chance of getting a victory in these two remaining matches, with two opposing teams like that then of course Real Madrid has better quality.
Although Brest are in a better position than Real Madrid in the table, but I believe it will not have any influence on Real Madrid, because I believe Real Madrid will also be able to beat Brest. There is nothing to doubt about Real Madrid in the Champions League, although they are not so good in this round, but when it comes to the knockout stages later, ofcourse Real Madrid will always be a team that is included in the title candidates whatever of the process.