"To be honest, we are not good enough right now," said the Norwegian midfielder in response to inquires about Celtic's Champions League credentials.
The angry crowd outside the tent in which the impromptu press conference was being held on Tuesday night were fully and raucously in agreement with this blunt assessment.
However, the 23-year-old shielded his countryman Ronny Deila from any blame after a team performance that dismayed the Celtic support and ensured that the Champions League group stages were beyond the Scottish champions.
"I don't think that is right," said Johansen of any attempt to target the manager for criticism. "We are a team. We lose and we win together and today we had a match plan and the players were not able to do it. So it is not his fault."
He said patience may be required before cohesion is found in Celtic ranks. "He needs time to put his stamp on the team," he said of Deila.
But he agreed Celtic did not deserve to be in the pot for the group stages after they had lost three of their last four qualifying matches.
"We need to improve as a team and as players. We have the Europa League now and we have to improve," he said.
Deila has attempted to impose a system on Celtic and it is obvious that some players are struggling with its demands of high energy and quick pressing. Johansen banished thoughts of any confusion in the ranks.
"The manager made it clear what he wanted us to do and we wanted to control the game but it was the players who did not manage it," he said.
There seemed to be an anxiety in the Celtic ranks that heightened when Maribor scored in the second half through Tavares but Johansen, who signed for Celtic in January for £2m from Stromsgodset, said nerves did not compromise the team performance.
"This is the type of game that everybody wants to play in," he said. "A lot of players in the team have played this type of game before so I don't think it is about nerves. We didn't play well, we didn't manage to keep the ball and the counter attacks hit us bad."
Maribor also won possession easily in the first half with Johansen, uncharacteristically, giving the ball away on occasion.
"We had to chase the ball a lot and that is not what we want at home," said Johansen of a haphazard and disjointed first half. "We wanted to control the game and entertain the crowd so it is disappointing."
He pleaded for patience with the team, citing that it was early in the season and the side still had a domestic treble to contest and the challenge of the Europa League to face. "Of course everyone wanted to play Champions League but we need to improve as players and as a team.
"It is tough now and it is going to be difficult but we need to do that."
He conceded that it was one of the most disappointing nights of his career, particularly as part of the lure of coming to Celtic was to play in the group stages of the Champions League.
He would not comment on the fans' protest, saying: "I wish to concentrate on the team and what I am going to do."