Neymar and Kylian Mbappe training together ahead of Paris Saint-Germain s trip to Lille Bertrand . AFP
Neymar insisted on taking the team's second penalty against Montpellier last Saturday after Mbappe had missed the first.
Mbappe did not celebrate after Neymar converted the spot-kick.
Galtier called the apparent differences between the two an "epiphenomenon", suggesting the spat was not a symptom of any deeper problem.
"We saw each other quickly the next day to iron out all that, to say what we had to say to each other," said Galtier told a press conference ahead of Sunday's Ligue 1 visit to Lille.
"We had a very pleasant week at work. Everyone worked well. I enjoyed all the sessions this week and this epiphenomenon disappeared very quickly, that is to say the day after our meeting."
Galtier said after the game that instructions "had been respected" regarding penalty takers.
"There was a precise order in this game, Kylian as number one and 'Ney' as number two."
Other potential penalty takers include Lionel Messi and Sergio Ramos, said Galtier, adding that it was "important for our strikers to score goals, to keep the confidence".
Against Montpellier, in his first competitive game since opting to stay in Paris rather than join Real Madrid, the 23-year-old Mbappe scored in a 5-2 win but cut a frustrated, unhappy and even isolated figure.
Last season, Mbappe was PSG's outstanding performer, scoring 39 goals in all competitions, while Neymar struggled.
Yet the 30-year-old Brazilian has seemed rejuvenated this season, scoring five goals in three games.
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