Portuguese forward Tiago Tomas had to be comforted by his teammates when he broke down in tears after his Stuttgart side warmed up for Thursday's Europa League visit to Celtic with a 3-1 win over Koln.
Tomas, who rejoined Stuttgart from Wolfsburg last summer, had come on as an 84th-minute substitute on Saturday for his first appearance since December, with reports in Germany later claiming the 23-year-old's father died in January.
Asked if he could explain the background, head coach Sebastian Hoeness said: "No, I don't want to - that's something personal.
"But it very public. It wasn't an injury or anything. It was something family related and that's probably why, after such a long time, when he's back on the pitch, the emotions came up. The guys tried to comfort him and give him strength."
Earlier, a double from fellow forward Ermedin Demirovic helped Stuttgart return to winning ways after last week's 2-1 defeat away to second bottom St Pauli.
The victory, Stuttgart's fifth in six games, lifts Hoeness' side up to fourth in the Bundesliga, although RB Leipzig will regain that spot should they beat visitors Wolfsburg on Sunday.
Asked how it set them up for their knockout phase play-off first leg at Celtic Park, centre-back Jeff Chabot said: "We expect a great game and excellent atmosphere."
Demirovic opened the scoring against 11th-placed visitors Koln after 15 minutes, slotting home from 10 yards after fellow forward Jamie Leweling headed into his path.
Koln struck back with 11 minutes remaining when Luca Waldschmidt pounced on a slack pass out of the home defence and set up strike partner Ragnar Ache for a clever chip over goalkeeper Alexander Nubel.
Demirovic restored the lead five minutes later as he volleyed home at the near post from centre-back Ramon Hendriks' superb curling cross.
The three points were wrapped up in stoppage time, Germany forward Deniz Undav volleying in from 12 yards from midfielder Angelo Stiller's pass.
Stuttgart have made a habit of goals in the final quarter of matches this season, something Hoeness put down to "believing in themselves until the end".
Demirovic has now scored 10 goals in 20 appearances this season, four in his latest five, but asked about his fine strike rate, the 27-year-old Bosnia and Herzegovina international provided a simple explanation. "I'm the striker - I score the goals," he said.