Portugal came from behind to beat Luxembourg 3-1 on Tuesday, moving top of World Cup qualifying Group A in the process.
Gerson Rodrigues scored his second goal in as many games to put Luxembourg ahead, but Diogo Jota, Cristiano Ronaldo and substitute Joao Palhinha sealed the points for Portugal.
Jota's equalizer – a header from inside the six-yard box – was teed up by the Liverpool forward's former Wolves team-mate Pedro Neto, who replaced Joao Felix in the 41st minute.
Another header for Diogo Jota! 🔥— ESPN FC (@ESPNFC) March 30, 2021
He now has 6 goals in 5 starts for Portugal 🇵🇹 pic.twitter.com/2NCiMXOvb9
Making his first start of the qualifying campaign, Joao Felix appeared to be struggling with an injury to his right ankle, seemingly sustained when he had a shot blocked in Luxembourg's box.
It was the youngster's only attempt, while he also failed to create a chance and completed just 18 of 25 attempted passes.
Neto, on the other hand, ended the match with two assists, for Jota and Palhinha respectively, and it was a performance that drew the praise of Santos, who hinted that it is difficult to fit Joao Felix into a certain role in his team.
"Neto had different movement, another dynamic, he looked for depth, he went looking for the ball," Santos told reporters.
"He always participated in defensive actions. Joao always had more difficulty. He has his own way of playing, he is not a combative player, we are not expecting that either.
"He has a lot of technical quality, he has the quality to make a difference, but we all have to be together so that these things can work."
It is an issue that has also stymied Joao Felix's Atleti career to date, with the 21-year-old delivering some quality displays at the start of the campaign, but scoring just twice in LaLiga since the turn of the year.
Ronaldo's goal was his 103rd for Portugal, taking the 36-year-old to within six strikes of Iran legend Ali Daei's record, while he has also scored in every calendar year since making his international debut in 2004.
The Juventus star squandered two gilt-edged chances to double his tally at 2-1, in what was a rather labored performance from the reigning European champions, and Santos acknowledged he has to strike a balance between playing to the strengths of the attacking talent he has available, while also remaining organized.
"Technical quality alone doesn't win here, if we don't balance these important factors," he added.
"It's not that the players don't want to. We had difficulties. But then there was an instant reaction, we scored in an important moment.
"The second half was [better]. The goals appeared and we could have scored more. We had opportunities."