The Spaniard joined the Gunners from Malaga just before the January transfer deadline, and was pitched into action against Stoke less than 48 hours later.
After a clean sheet in that game was followed by an even more impressive shut-out against Sunderland last Saturday, Monreal's new captain believes he has already shown himself to be cut out for Premier League life.
He has done well, and you can see that he's a good player with plenty of qualityVermaelen on Monreal
"He joined us on the Thursday, trained on the Friday and then went straight into the side. I've been impressed with the way he has started here," Vermaelen told the official matchday programme.
"He has done well, and you can see that he's a good player with plenty of quality. He's quick and solid, and plays for his national team - he's also a nice, relaxed guy to talk with. I think he will be a great signing for us.
"He's had a tough start with two typically 'English' games, completely the opposite to what he'll have faced in La Liga, but he's shown that he can cope and I have no doubt that he will do well in the Premier League."
Blackburn pose the next challenge and while Vermaelen is aware that, although plying their trade in the Championship, many of Michael Appleton's side are more than accustomed to playing in the top flight.
Read the full interview in the Blackburn Rovers programme
"It’s nice to be at home in a cup tie, but we can’t take anything for granted," he said. "Blackburn may be a Championship side, but they have plenty of experience of the Premier League - and we know all about guys like Danny Murphy, who has a proven track record at this level.
"They’ll be used to this kind of game, so we need to work hard and treat it as another Premier League fixture.
"We’ll have to be focused, playing our own game and showing our own qualities, and then hopefully we’ll have enough to win."Copyright 2017 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source