Fenerbahce left-back and Werder Bremen centre-back are due at the Gunners' London Colney training ground to finalise personal terms on Tuesday ahead of completing moves
Arsenal are closing in on the signings of £14.1 million defensive duo Andre Santos and Per Mertesacker, Goal.com can confirm.
The Brazil left-back and Germany centre-back are due at Arsenal's London Colney training ground on Tuesday to undergo medicals and finalise personal terms.
Arsenal have agreed a £7.9m fee with Werder Bremen for Mertesacker, 26, and will pay Fenerbahce £6.2m for Santos, who is 28.
Werder general manager Klaus Allofs has confirmed that Mertesacker has long wanted to move to the Emirates.
He told Sportinformationsdienst: "Per has had the wish to force his career [for] some time. He wanted to play for a big European club. Arsenal was always his favourite club."
Werder Bremen's media director Tino Polster has also stated that the defender is in England as talks continue over a move.
"Arsenal has sent a request to us. Both clubs are in talks. Per travelled to London," Polster said.
Reports in Germany say that 6ft 6in Mertesacker has agreed an £80,000-a-week deal while Santos is said to have negotiated an Arsenal contract worth £40,000 a week after they had met Fenerbahce's asking price for the attacking full-back.
Arsenal executives are busy wrapping up deals in the last two days of the window after manager Arsene Wenger acted to rescue a season that has been in danger of falling apart in the opening few weeks.
South Korea captain Park Chu-Young, 26, has completed a move for an initial £3m - although this has yet to be announced by the club - and will beef up Wenger's striker options.
Mertesacker and Santos will also be expected to slot straight into the Arsenal team after the international break.
The German will provide the physical presence that was absent during Sunday's 8-2 humiliation against Manchester United, while Santos will leapfrog the injury-plagued Kieran Gibbs as the first-choice left-back.
They will provide the experience that was so lacking at Old Trafford, where the likes of Carl Jenkinson, Johan Djourou and Laurent Koscielny were torn apart by United. The fourth member of that defence, Armand Traore, has already signed for QPR.
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