Borussia Dortmund hope to have Mats Hummels fit for Tuesday's crucial clash with Bayern Munich after the defender went off injured in a 2-0 victory at Wolfsburg.
Dortmund ensured they would go into the midweek visit of the leaders still within four points after goals in each half saw off the sixth-placed team at the Volkswagen Arena.
But they suffered a blow when former Bayern centre-back Hummels, who has 70 caps for Germany, went off for Emre Can at the halfway stage.
Sporting director Michael Zorc said on his club's website: "Overall, it was a deserved win with a good first half. In the end we also comfortably saw out the win.
"Right after the break, we had a slight phase of weakness. Wolfsburg were dominant and had one or two chances to score.
"Maybe we had to reorganise ourselves after Mats Hummels' injury-enforced exit. He has had problems with the Achilles tendon for some time, but we hope that he can play again on Tuesday.
"Overall, it was a decent performance. Playing in Wolfsburg is never easy."
Raphael Guerreiro put the visitors in front in the 32nd minute and Achraf Hakimi fired home after a 78th-minute counter-attack – with the help of a strong run from substitute Jadon Sancho – before the late dismissal of Felix Klaus ended any Wolfsburg hopes.
Wolfsburg head coach Oliver Glasner said on his club's website: "We're obviously disappointed as we had big plans but didn't quite deliver them on the pitch.
"We were well organised and gave away very few goalscoring opportunities, but we were too error-prone when we had possession. In that respect, Dortmund deserved the half-time lead.
"We did better after the break and I'm pleased with the performance there, especially the first 25 minutes. We needed to equalise during that period but then conceded the second goal on the counter."