Lucas was replaced at half-time after suffering what Atletico described as a "strong facial trauma" in a 1-0 defeat away to Sporting CP, Diego Simeone's men heading through 2-1 on aggregate.
"Arsenal rode their luck against CSKA and there was a chance they could have gone out".
Torres has made 150 appearances for Atletico since returning to the club in January 2015, initially on an 18-month loan deal from AC Milan.
Atletico also beat Liverpool in the Europa League semi-finals in 2010 before going on to lift the trophy.
In the Champions League we have of recent years been knocked out by Europe's elite, Bayern and Barcelona quite regularly. If they win the cup, they'll jump that phase and be in the group stage. Therefore, any possibility of paying for breaking the contract is nearly impossible and neither is the player looking ready for the task of leaving the club of his life.
The return match is May 3 in Madrid. "Whatever happens in the season, winning or losing, they deserve my respect for what they have done".
Currently, 13 points behind arch-rivals Spurs who sit in fourth spot, a Champions League spot looks highly unlikely meaning the Europa League is their last resort for success.
Atletico were 2-1 aggregate winners against Portuguese side Sporting Lisbon in the quarter-finals to reach the semi-finals.
- Joint strikes in Syria draw mixed reactions from the Middle East
- Two Vancouver-area police officers arrested, released in Cuba
- 'Consequences' for Syria strike: Russian Federation
- Over 100 cruise missiles fired at Syria, many intercepted: Russian Federation
- Trump Says US-Russia Ties 'Worse Now' than During Cold War
- Zuckerberg addresses rumours about Facebook tapping your microphone
- Use of chemical weapons in Syria 'simply inexcusable': Mattis
- President Trump to Look at Re-Entering Trans-Pacific Partnership
- No Toby Alderweireld, no John Stones: Tottenham XI vs Man City
- Kevin Love: LeBron James' Looming Decision Could Affect Cavs' Playoff Run