The Manchester City striker was substituted after 67 minutes at the Estádio do Dragão after appearing to signal towards the Norway bench for a change. His departure initially raised concerns ahead of City's trip to Liverpool, but coach Ståle Solbakken said the decision had been planned because of Haaland's accumulated workload.
"We expected 60 minutes after the conversation we had yesterday, and he managed 65 minutes," Solbakken said.
The 26-year-old had completed 90 minutes in each of Norway's previous three matches during an unusually demanding international period. Solbakken said a number of players were leaving camp early to take advantage of several days' rest provided by their clubs.
"It wasn't just Haaland who left early. There's a whole group leaving now. They need to breathe. The clubs have given them a few days off," Solbakken said.
Haaland's workload has been a growing concern during the international break. He had already been described as exhausted after Norway's earlier matches, while the striker's involvement at club level has remained relentless.
Norway defender Leo Ostigard defended Haaland after the Portugal defeat, stressing the demands placed on a player who is expected to perform at the highest level in almost every match.
"It was a long camp and those who played the most had to go to the limit. Of course we want to have him on the pitch as much as possible, but he plays an incredible number of games and is also just a human being," Ostigard said.
Patrick Berg made a similar point after playing 87 minutes against Portugal, saying it was unsurprising that Haaland eventually ran out of energy after playing the previous three matches.
"We would have liked to have had him on the pitch, but when the energy runs out, the body gives in," Berg said.
Haaland now has a short period to recover before City travel to Anfield on Sunday. The match against Liverpool will be followed by a Champions League meeting with Paris Saint-Germain three days later.
The early substitution therefore appears to have been part of a deliberate workload-management plan rather than a response to an injury, although Haaland's condition will remain closely watched ahead of City's return to action.