Croatia headed into the tournament looking for a repeat of their 2018 success when they reached the final.
However, Morocco are a decent side and were expected to prove a stern test for Luka Modric and co.
At the time of writing, neither side has been able to break the deadlock.
Morocco have pressed Croatia well and created several chances through Hakim Ziyech.
Croatia, meanwhile, had limited chances in the first 45 and did not manage a shot on target until the 45th minute, with Vlasic forcing a good stop out of Bona after being played in by Sosa.
Luka Modric, who won the Ballon d’Or in 2018 after taking Croatia to the World Cup final, was in from the off vs Morocco and looked in top form once more.
Modric also set a record after starting on Wednesday, becoming the first player to play in the World Cup and European Championships in three different decades.
Cristiano Ronaldo will become the second player to do so when his Portugal side face Ghana on Thursday.