With the transfer deadline less than two day away, Arsenal boss Arsene Wenger is stepping up efforts to bring an experienced centre back.

Apparently, there are two potential targets who won't be joining the Gunners. Werder Bremen defender Per Mertesacker said last week that he will not leave the German club for Arsenal, and negotiations have not reopened. Meanwhile, Blackburn have agreed on a £5 million deal for Birmingham's Scott Dann, according to Daily Mail.

However, Arsenal have three strong centre back options: Bolton's Gary Cahill, Everton's Phil Jagielka, and Chelsea's Alex. It seems apparent that one of these candidates will be a Gunner by the end of Wednesday.

Of the three, Cahill appears to be the most likely to join the club. The Telegraph reports that Arsenal will raise their bid to £12 million for Cahill, with the possibility of an additional £3 million based on appearances. 

The 25-year-old is in the final year of his contract, and there doesn't appear to be any other serious bidders aside from Tottenham, who may have to unload Peter Crouch in order to make a stronger offer. It could be too late for the Spurs to make such a deal.

Phil Jagielka is considered the preferred option, but Everton want far more than the £12 million Arsenal has offered. The Guardian reported that David Moyes wants at least £20 million for the 28-year-old. Jagielka is an ideal candidate for Arsenal, because he could also play holding midfielder -- a position where Arsenal are rather thin.

The latest Arsenal reports suggest that the Gunners are interested in adding 29-year-old Alex. The Brazilian has had some recent struggles, so Wenger probably wants to spend less than the Blues' £10 million price tag. The long-time Arsenal boss is known for seeking bargains, so if Alex joins the Gunners, it will likely be a deal worth between £6 million and £8 million.

An interesting factor in the centre back negotiations is Nicklas Bendtner. The Danish forward has been linked with a move to numerous clubs for several weeks, and might be used in a swap deal since he's valued at roughly £10 million.

Wenger could also make a late bid for Blackburn's Christopher Samba.