Carlo Ancelotti says Bayern Munich are holding their breath over David Alaba for Wednesday's German Cup semi-final against Borussia Dortmund after the Austria global injured his knee.
Arjen Robben and Thiago Alcantara equalised on-loan Bojan Krkic's second-minute opener and then Daniel Brosinski's penalty just before the break.
Defending champions Bayern extended their advantage to nine points but, with their nearest rivals having a match in hand at Schalke on Sunday, and five games still to play, the mathematical possibility of catching them has improved slightly.
Thiago Alcántara's late equaliser spared Bayern Munich from what could have turned out to have been an embarrassing home defeat to Mainz 05 - the runaway Bundesliga leaders were forced to bounce back after going behind twice at the Allianz Arena.
"It wasn't easy to play after the shock against Real Madrid, but we could have done better".
"As a player, I consider myself to have been really privileged to have had the chance to enjoy playing in the four major leagues as a professional and days like today make it all the more thrilling".
Bayern finally made their 75 percent possession count with Thiago equaliser from 17 metres out.
Gladbach fought back with captain Lars Stindl equalising before Dortmund skipper Marcel Schmelzer put the ball in his own net to put the hosts 2-1 up early in the second half.
Dortmund, eliminated by Monaco from the Champions League this week, are on 56, a point ahead of Hoffenheim, who drew 1-1 at Cologne on Friday. We should have done better.
Hertha Berlin stay fifth - and on course for a Europa League berth next season - after Vedad Ibisevic's second-half goal sealed their 1-0 win over Wolfsburg, who drop to 14th.
Augsburg occupies the relegation playoff spot after a 3-1 loss at Eintracht Frankfurt.