Sixth-placed United have been held to draws in six of their last eight league games, including consecutive 1-1 results against Arsenal, West Ham United and Everton.
Jose Mourinho's men are 13 points behind league leaders Chelsea, who are on 34 points, three more than Arsenal and four ahead of Liverpool and Manchester City.
“Of course, 13 points is a long distance, especially when one team is winning games with the quality of Chelsea,” Guardiola told reporters.
“So it is not easy. But to be in the first four? Of course.”
“I saw the games against Stoke and Burnley, and other ones at Old Trafford. They deserved by far to win the games but football is like this.
“United have the quality, the history, the manager and the players to be there.”
While no one in Premier League history has gone on to win the league with a 13-point deficit, United did overturn a 12-point gap to Newcastle in 1996.
United will hope to break the cycle on Sunday when they host Tottenham Hotspur, who are one place above them in the table.
Original source: United can finish in top four, says Guardiola