After taking over the reins from Frank Rijkaard in 2008, Guardiola lifted 14 major trophies for Barcelona in a four-year spell which included two Champions League titles.
While Mourinho enjoyed some success at Real Madrid and a bitter rivalry with Guardiola, he was left in the shade and returned to Chelsea after his spell at the Bernabeu ended sourly.
Guardiola meanwhile, is now on course to lift the Premier League title and could finish this season with a stunning treble.
And Laporta who was responsible for promoting Guardiola from managing the ‘B’ team, explained his decision.
“We had our first conversation with Pep in January that year. We thought that Frank Rijkaard should finish the season and that Pep could be involved in the first-team staff,” Laporta told the Daily Telegraph.
“But he told me that he would prefer to continue with the second team because he was so sure that they would get the championship.
“So we agreed that he would finish the season with the second team and then be the coach of the first team.
“I told him ‘Pep, we are sure it’s a good decision’, and he told me, ‘I believe you are right because we will win everything’.
“He said this joking, but you know at the end of his first season we had won everything – it was the perfect season.
“There were other options and some people, especially the media, were pushing for them, but we were focussed on Pep [Guardiola].
“I had the responsibility to manage Football Club Barcelona and sometimes you need to surprise to change the history. Thanks to Pep, we did it.”