Poland's fightback to draw 1-1 against the 10 men of Portugal proved they can play well without talismanic striker Robert Lewandowski, according to head coach Jerzy Brzeczek.
Arkadiusz Milik's second-half penalty earned relegated Poland a Nations League point that ensured them a place in pot one of the Euro 2020 qualifying draw at the expense of Germany.
Andre Silva's header had given Portugal the lead in the first half but Danilo Pereira's foul on Milik saw the hosts concede a penalty and the midfielder sent off before the encounter in Guimaraes ended all square.
Lewandowski played in Poland's previous game, which ended in a 1-0 friendly defeat to the Czech Republic, before withdrawing from the squad and returning to Bayern Munich with a knee injury.
Brzeczek told TVP Sport: "We played a good game. We lost a goal quite quickly but we did not lose self-confidence. This is the most important thing, that we did not give up.
"Something important happened: we proved we can play well even without Robert Lewandowski. I am sure it will help us in the future.
"I am also glad of the level of our defence. Again, we proved that without Kamil Glik, another key player, we can do well.
"I am not glad that I have not won any of my six games as Poland coach, but I am sure that this difficult path we are going through will make us stronger."
Portugal coach Fernando Santos was critical of his side's performance for the second consecutive match, despite seeing them safely qualify for the Nations League Finals in 2019.
A goalless draw with Italy secured Portugal's passage into the Finals, but Santos lambasted his side's mistakes in both games.
"I'm proud that we're through to the final four, but I'm not pleased with the game," Santos told reporters.
"We could've done more and made too many errors.
"In the first half we had more possession but didn't create enough. We improved in the second half but once we have given away the penalty and went down to 10 men it was more difficult.
"Poland weren't great but we gave them good chances. We tried to fix this in the second half and we improved but then they scored and with 10 it's always harder."