Inter Milan moved top of Serie A on Saturday after hammering high-flying Como 4-0 at the San Siro, ahead of the visit of struggling Liverpool in the Champions League.
"While it is regrettable to have to let these games go ahead, this decision is exceptional and shall not be seen as setting a precedent," UEFA president Aleksander Ceferin said in a statement.
Lionel Messi has been linked with a move away from the MLS this summer.
Pope Francis died at his home in the Vatican on Monday aged 88 after suffering a stroke.
Inter Milan saw off Como 2-0 on Monday to stretch their unbeaten run in Serie A to 11 games and move back to within three points of leaders Atalanta.
Lazio romped to a 5-1 away win at Como in Serie A on Thursday while city rivals Roma bought some time for under-fire coach Ivan Juric with a 1-0 win over Torino after being booed by their own fans
Romelu Lukaku starred again for Napoli by scoring once and setting up two more goals in Friday's 3-1 win over Como which ensured top spot in Serie A for at least another week
In-form Serie A side Como, coached by Cesc Fabregas, is expected to provide a stern test to Antonio Conte's Napoli.
Gian Piero Gasperini's Atalanta have lost three of their opening five Serie A fixtures and were unlucky to only draw 0-0 with Arsenal in the Champions League on Thursday.
Atalanta thumped Lecce 4-0 on Monday as doubles from new boys Marco Brescianini and Mateo Retegui gave the Europa League holders a hugely impressive start to their Serie A season.
Como suffered multiple bankruptcies and tumbled down the pyramid after being relegated from Serie A little over two decades ago.