Coach Vicente del Bosque gave De Gea a vote of confidence by selecting him ahead of captain Iker Casillas for the match in Skopje, when Spain’s comfortable win thanks to an own goal put the holders two points clear at the top of Group C and close to securing their berth at the finals in France next year.
De Gea’s planned move to Real Madrid fell through in farcical fashion last week when the paperwork was delivered too late and United coach Louis van Gaal has not used him this season while the transfer sage dragged on.
“I felt good, I really wanted to play,” De Gea, who had little to do during the game, told Spanish television.
“Now I need to keep working and see if I have some good fortune at my club as well,” added the 24-year-old former Atletico Madrid keeper.
“My future will be the same as now: remain calm, keep working and improving. In concrete terms, enjoy my football. I am happy.”
Spain, who have not conceded a goal in six qualifiers, lead the section on 21 points, two ahead of Slovakia who were held to a 0-0 draw at home on Tuesday by an Ukrainian side further three points behind in third.
The nine group winners and runners-up and best third-placed side qualify directly, while the eight remaining third-placed teams contest playoffs for the last four spots.
Chasing a third straight continental triumph, Spain can make sure of their place with a home win over Luxembourg on Oct. 9 before they play in Ukraine three days later.
Although Spain enjoyed a comfortable win against bottom-placed Macedonia, Del Bosque, who fielded a weakened team, was not happy with the performance.
“We have to recognise that we did not play well,” he told a news conference.
“We could single out individuals but the right thing to do is to admit there was a general dip in our play.
“After the goal we were very static, slow, on the back foot and lacking in depth.”
“They did not dominate us but we were not comfortable and they had the odd chance on the counter attack.”
(Writing by Iain Rogers, editing by Amlan Chakraborty)