Guardiola hopes Manchester City can 'clear heads' and come back stronger after break
Saturday's loss marked the first time City, second in the standings, have lost four in a row in all competitions since August 2006. Guardiola has now lost four successive matches for the first time in his otherwise glittering managerial career.
City have been rocked by injuries with Nathan Ake, John Stones, Jack Grealish and Ruben Dias all sidelined on Saturday, alongside longer-term absentees Rodri and Oscar Bobb.
"Of course, it's November, we are not far away (from rival teams) in this position before the international break," Guardiola said.
"(The key to) winning games is the people come back fit, the people came back and can play, can train and then improve our results.
"(We need to) clear our heads, go into the international break, and for players to come back fit. The success that they had the last seasons were because we had fewer injuries.
"I would like the players to be consistent and be able to play at the level we played in the first half."
Erling Haaland scored in the 23rd minute and had a couple of narrow misses in a first half where City had five shots on target.
But Brighton were much-improved in the second half against a sluggish City and substitutes Joao Pedro and Premier League debutant Matt O'Riley scored to secure the victory.
"So the first half we should, not open the game, it was open, but have the control, and we could not, and we are not at the level right now to sustain 90 minutes," said Guardiola.
"In the first half, we were brilliant, but of course, the second half sometimes fatigue (kicks in) and they make changes and they change the pace, and we cannot do it right now and we lost the game."
City had previously lost to Tottenham Hotspur in the League Cup, Bournemouth in the league, and then suffered a 4-1 thrashing by Sporting in the Champions League on Tuesday that had Bernardo Silva saying City are in a "dark place."
"It's down to us as a group of players to make sure that we're fighting for this great club," captain Kyle Walker told Sky Sports.
"It's tough to take, and I can assure you everyone wants to turn it around as quickly as possible."
Guardiola's second worst stretch as a manager was with Bayern Munich during the 2014/15 season, when they suffered three consecutive losses plus a penalty shootout defeat in the German Cup.