Antoine Griezmann punished Laurent Koscielny's slip to score in the 82nd minute as the Spanish visitors – who had Sime Vrsaljko sent off after 10 minutes – grabbed a 1-1 draw at Emirates Stadium in the first leg of the semi-final.
The Frenchman's strike cancelled out compatriot Alexandre Lacazette's opener, with the hosts spurning chances to extend their advantage against 10 men before conceding a late equaliser.
Atletico's home record has been excellent this season, conceding just four goals at home in La Liga, and just nine goals in 26 games in all competitions.
Yet midfielder Wilshere – who provided the cross for Lacazette's goal – is confident Arsenal can cause problems for their opponents in the return fixture at the Wanda Metropolitano next week.
"We knew what type of team they are – they were always going to try to hit us on the counter and I thought we dealt with that pretty well and defended really well," the England international told the club's website .
"They had a bit of luck off the keeper but at this level that's a massive goal for them.
"But at the same time we're confident that we can go to Madrid and with the chances we created, we are definitely going to create some chances and hopefully we'll put them away."