John Carver’s side suffered their seventh successive defeat in the Premier League, as they went down 3-2 to Swansea City at St. James’ Park.
De Jong made his long-awaited comeback fro injury in the 74th minute and scored a goal, but he was not pleased with the final result.
"I'm glad to be back but it's not about me today,” Newcastle’s official website quotes the 26-year-old Netherlands international as saying. “It’s about the team and I want to help my teammates as much as possible.
"We have some difficult games ahead. Everybody is disappointed but we have to fight and focus on winning points.”
Newcastle are now 14th in the Premier League table with 35 points from 34 games, just five points above the relegation zone. At the start of today’s games in the English top flight, the Magpies were seven points clear of the bottom three.
Carver’s side are back in action next weekend, when they take on fellow relegation candidates Leicester City away from home at the King Power Stadium.
Not so long ago Newcastle looked set to finish the season in mid-table mediocrity, but heading into the final weeks of the campaign, there is a good chance that they could go down to the Championship.