Van der Linde scored just five points across the two races at the 2.297-mile track in Germany, and his lack of one-lap pace was a particular cause of concern as he failed to qualify higher than 15th in his BMW M4 GT3.
The South African's woes were compounded by a botched pitstop in Saturday’s opening contest, with the Schubert mechanics dropping his car off the jack while the front-left tyre was still to be fitted.
Sunday’s race panned out comparatively better, van der Linde charging from 15th to 12th in the opening laps before finishing 11th at the flag - although a battle with Benhard Porsche driver Ayhancan Guven allowed Winward Mercedes’ Auer to get through and break inside the top 10.
Schubert team manager Marcel Schmidt was naturally disappointed after the weekend, with new signing Rene Rast also failing to finish higher than fifth, but expects things to get better when DTM heads to Zandvoort for the second round on 24-25 June.
“For Sheldon it was simply a jinxed weekend,” Schmidt said.
“He was incredibly unlucky with the timing and was therefore in a difficult starting position in both races.
“He made the best of it in the second race and even these five points can make a difference at the end.
“The mistake at his pitstop on Saturday certainly annoyed us the most, but it hits everyone at some point.
“We'll do better at Zandvoort and, of course, we're hoping that the ADAC will use the findings from the season opener to tweak the Balance of Performance to ensure a level playing field.”
Van der Linde was particularly frustrated by his struggles in qualifying, which left him with too much ground to recover at a track where overtaking opportunities are fairly limited.
The 24-year-old started the opening race of the weekend from 19th on the grid, 11 places behind BMW newcomer Rast, after encountering traffic in qualifying, while he was 15th-fastest and half a second off the pace on Sunday.
"The weekend in general was just not strong enough,” he rued.
“If you don't start at the front here at Oschersleben, you've got a bad hand in the race. We'll be working over the next few weeks to get our qualifying performance back.
“Last year we were very strong on one lap. If we can do that, everything will come a little easier in the race.
“The results are not a dealbreaker for us. The season is still long and many things will happen.
“We'll give everything to be at the front again at Zandvoort and score the big points. The team and I know that we are capable of doing that and I have full confidence in the Schubert Motorsport crew."
