The defender sealed an £8 million move to north London on Thursday and his new manager is sure the Spaniard will add much-needed quality to the left-back department
The 26-year-old agreed a long-term contract with the Gunners on Thursday evening to become their sole addition of the January transfer window.
And Wenger has revealed that the north London club had been watching the Spaniard over a prolonged period.
“We are delighted that Nacho Monreal has agreed to join us,” Wenger told the club’s official website.
“We have been monitoring him for some time now and are really pleased that we’ve been able to agree this move today.
“Monreal is a strong left-sided defender with good experience at both club and international level. He is a technically gifted player, a good crosser in the final third and strong in the air.
“Monreal will add quality to our squad and of course, to our defensive unit. We all look forward to him playing for us.”
The former Osasuna defender is in line to make his Gunners debut on Saturday when Arsenal entertain Stoke at the Emirates Stadium.