Ajax manager Erik ten Hag has said that Barcelona star Lionel Messi has not reached the same level since Pep Guardiola left Camp Nou in 2012.
Guardiola took over as Barcelona manager in 2008 and during a four-season run, he led the Blaugrana to a stunning period of success that included three La Liga titles, two Copa del Rey wins and two Champions League triumphs.
Messi also experienced an extraordinary run of individual success during this period, winning the Ballon d'Or in four consecutive years between 2009 and 2012.
During Guardiola's final season in charge the Argentine also reached his career high in league goals, netting an incredible 50 times in 37 La Liga appearances in 2011-12.
Since Guardiola left Barcelona have won the Champions League just once in eight seasons, with Messi winning the Ballon d'Or two times in that timeframe – though Barca have won La Liga five times during that span.
Ten Hag believes that during Guardiola's reign, Messi was able to be more of a team player and under subsequent coaches, the Argentine has seen his level dip at times below where it was under the Spaniard.
"Messi was one of the leaders, but he also worked for the team and excelled as a result. He has never been as good as under Guardiola," Ten Hag told Voetbal International.
"Barcelona has not won much in European terms in recent years either.
"Messi still excels, but now also occasionally goes through the lower limit. It was never like that under Guardiola.
"Pep has guts, he dares to be pioneering and innovative."
After leaving Barcelona, Guardiola would take over Bayern Munich ahead of the 2013-14 campaign. In Bavaria, Ten Hag had the chance to work alongside Guardiola as the Dutchman coached Bayern's reserves.
Ten Hag would leave to become head coach of Utrecht in 2015. The following season Guardiola would also depart Germany, taking over Premier League giants Manchester City.
After leading Ajax to a stunning 2018-19 campaign that saw them win the Eredivisie and reach the Champions League semi-final, Ten Hag has been linked with managerial positions at some of Europe's biggest sides.