Since returning to his boyhood club three years ago, Pep Guardiola has established Barcelona as the premier team in European football with its mesmerizing, collective style of play.

Now, he has the chance to cement his legacy as the most successful coach in the Catalan club's 112-year history - and perhaps one of Europe's finest - with more silverware in what could be his final season.

Under Guardiola, Barcelona has already set itself apart with two Champions League trophies. A fourth consecutive Spanish league would match the club record set by Johan Cruyff's ''Dream Team,'' which Guardiola played for, in the 1990s.

''The fourth season is different from the first, the motivations are different,'' Guardiola said. ''It's a little calmer, but I still have the same enthusiasm and desire to play football well.''

Real Madrid should again be Barcelona's challenge for the domestic championship, a title which may prove key to whether Guardiola bids adieu to the Camp Nou.

The 40-year-old Guardiola caused alarm near the end of last season when he said his ''time at Barcelona was coming to an end.'' Guardiola resisted pressure to sign a long-term contract and agreed to a one-year extension until June 2012.

Former Barcelona player-turned-coach Carles Rexach, who led Guardiola from 1991-96 as an assistant to Cruyff and later as coach, believes Guardiola is playing coy to keep his players concentrated.

''It's (Guardiola's) way of maintaining the team's focus, but he also knows it's true that with time there is more wear and tear,'' Rexach told The Associated Press in a telephone interview. ''He experienced it with me and Cruyff during six years. It is difficult to maintain the tension, and four or five years represents an era. Players are no longer at their top level.''

The 64-year-old Rexach, whose 656 games played are second all-time for Barcelona, believes Guardiola could stay on if ''Barca continues to play like it has until now, if it wins the Champions League or La Liga.'' The attitude of the team will be critical, Rexach added.

Rexach was Guardiola's coach in 2001 when the lanky midfielder known for his precision passing abruptly left Barcelona after 11 seasons, six Spanish league titles and the club's first European Cup.

''He saw that the cycle was over,'' Rexach said. ''I think Pep (now) has an advantage because he experienced all that as a player. He went through the decline of the team because in that moment there wasn't a generational change. We didn't make the necessary changes, and he has this experience.''

Guardiola said he will stop when his players grow tired of him, or vice versa.

While Barcelona did bring in reinforcements with the signings of Arsenal midfielder Cesc Fabregas and Chile forward Alexis Sanchez, Guardiola appears confident his core players are good for another championship run.

Lionel Messi is still only 24 years old and has every possibility of winning his third consecutive Ballon D'Or with another spectacular season, especially with players like Xavi Hernandez, Andres Iniesta and David Villa surrounding him. While Gerard Pique has stepped up to assume the leadership role vacated by the now oft-injured Carles Puyol, defensive frailties may be the Catalan club's biggest hurdle.

''Pep Guardiola is the key to our success,'' Pique said. ''He is a great coach with a great capacity to motivate his players.''

Besides the pressure of the titleholder, Barcelona confronts a reinforced Madrid team led by the abrasive Jose Mourinho, who has repeatedly promised better things in his second season. Last year, Madrid trumped Barcelona in the Copa del Rey final but fell short in league and in the Champions League semifinals.

Whether or not an era for Barcelona continues or concludes this season, Rexach believes Guardiola knows he is approaching that critical point when either the team can deliver yet another trophy, or begin to show signs of decline.

''I have told (Guardiola) if you have a good team you have to squeeze everything out of it. (Then) he has to look to make a change before the team dies out,'' Rexach said, explaining that often it is easier for a new coach to make those tough choices.

''Each season it gets harder,'' he said. ''First, Barca is the team to beat, and second, everyone is increasingly analyzing ways to do so. Staying at the top is harder than getting there.''