Lionel Scaloni admitted Argentina needs to improve, conceding they were fortunate to see Switzerland's Breel Embolo sent off during their 3-1 extra-time win in the World Cup quarterfinals.

The Argentina coach did not hide his relief after a difficult night against a physical Swiss side in Miami.

"We suffered, we knew they were a very physical team and they caused us a lot of difficulties," Scaloni was quoted saying after the match by Brazilain outlet Globo.

"The truth is that today we were lucky to have one player sent off.

"The team needs to improve, but winning is always better. What this team did was historic," Scaloni said.

Despite the scoreline, Argentina were made to work hard by Switzerland throughout the contest.

The pattern echoed their previous knockout matches, where Argentina entered as favourites against Cape Verde and Egypt but were dragged into dramatic finishes.

Embolo's dismissal, for a second yellow card after a VAR review, proved a turning point in a tie Argentina had led before being pegged back.

Scaloni's side ultimately needed extra time to see off their opponents, with the numerical advantage playing a role in the eventual outcome.

With the victory secured, Argentina have booked their place in the semifinals, where they will face England next Wednesday in Atlanta.

The other semifinal will see France take on Spain on Tuesday in Dallas, completing the last-four lineup.