Manager Arsene Wenger accepts Arsenal will have "to be creative'' in the January transfer window, but has complete faith Nacho Monreal can provide "quality'' cover in central defence.
The Gunners have seen their squad decimated by injuries, with England midfielder Jack Wilshere ruled out for three months after ankle surgery earlier this week and captain Mikel Arteta set to be sidelined by a calf problem.
Wenger revealed the club would try to "rectify'' their defensive options when the transfer window re-opens, and have been linked with a move for Aston Villa's Ron Vlaar.
However, the Arsenal boss insists bringing in any new player is not a matter of just simply writing out a cheque and shaking hands.
"You have to give us time. We do our job as always. This season we bought five players who are all top quality, so I think we have done really well on the transfer market and we try to repeat that in January,'' said Wenger, whose side will look to build on the midweek Champions League win over Borussia Dortmund when they travel to West Brom for Saturday's lunchtime Barclays Premier League kick-off.
"However, to buy football players is not like you go into a supermarket and just say: 'I want to buy a right-back or a centre-back.' It is to find the right quality.
"If you go out tomorrow you will see that everybody looks for the same positions everywhere, so it is not as simple as it looks.
"In January, it makes it even more difficult because players are even less available than in June or July, but we will try to be creative and have one or two good ideas.''
Laurent Koscielny is expected to return from his Achilles problem at The Hawthorns.
With France full-back Mathieu Debuchy expected back before Christmas from a serious ankle injury, Wenger feels he will have plenty of defensive cover and has been impressed with Spain international Monreal's switch into the middle alongside Per Mertesacker.
"He is playing very well, he doesn't get enough credit because against Manchester United, against Dortmund, he was in the top three for me with the quality of his performance,'' said Wenger.
"I tested him (at centre-back) before the season started in the Emirates Cup tournament and I could see that he understands and reads the game well. It is the most important quality in this position.
"Of course, after that there is the question mark 'can he cope with the physicality of this job?' because he does not have a major frame, but game by game, he becomes more aggressive because he understands the game, he can get in front of people and that is a very important quality.''