Right back is a position that has seen decent stability for Newcastle United for the past 4 years, starting with the loan of Danny Simpson from Manchester United in August of 2009. The Man red academy product would make 125 appearances for Newcastle United over those 4 years. It will be hard to know in the 'he said/he said" of football whether the club were low-balling Simpson, whether they had grown tired of his highly publicized relationship with "reality star" Tulisa and the late London nights that accompanied or whether Danny Simpson just wanted to move on (which probably entered more into the conversation after Newcastle, you know, went and bought his replacement in January).
Generally speaking, there was not much to complain about Simpson in the Newcastle defensive half. Positionally, he could cover his position and provide accurate support into the center when necessary. Few will forget the 11-12 season that seemingly saw Simpson constantly in the eyes of Twitter with the #SimmoOffTheLine hashtag. Unfortunately, it was that same season that would see the beginning of the end for Danny (at least so far as the support were concerned). As Alan Pardew shifted to a more and more attacking and wing-oriented style, Simpson was asked to push into the attack more and more. He certainly had his moments in such a role, but unfortunately, they were largely overshadowed by his propensity to get dispossessed in a forward position and fail to track back which seemed to lead to a disproportionate number of goals conceded. Following the aforementioned purchase of France international Mathieu Debuchy, any handwriting on the wall became etched in stone and a new era would begin.
With his reputation greatly enhanced by a solid performance at Euro 2012 (something something Soccernomics), Debuchy was described as "a winger in a defender's body" and was meant to provide even more in the attack while staying solid in the back (obviously). Based on his appearances thus far in a Newcastle United shirt, Debuchy is truly the anti-Simpson. He has shown flashes of the offensive brilliance that we expected from him as we learned about him over multiple transfer windows, and is the advertised upgrade we were promised in that way. Defensively, however, he struggled. His time as the starting RB for Newcastle is marred by numerous hidings at the hands of opposing players, sloppy penalties conceded and flat out erratic play at the back.
Some players take a little while longer to acclimatize to the English game than others (see Coloccini, Fabricio), and the hope will be that in his first full season Debuchy will progress in the attack while making large strides on the defensive end. Long-term, he should prove out to be an upgrade over Danny Simpson, however as it stands now Debuchy's replacement of Simpson must be considered a wash. The club will be counting on his ascension - a look down the depth chart at the right back position is, well... populated by players intended for other positions.
Based on the latest squad rosters on the official site, there is not a second "true right back" per se on the squad outside Davide Santon, who is the starting left back. An injury or other absence to Debuchy is going to have a domino effect across the defensive line, leading to up to 3 changes to account for one player missing. Especially early on in his time with Newcastle (and before the purchase of Debuchy), there have been calls for Santon to take over completely at right back, and he has had some matches at the position across several competitions as well as some time this preseason. Although RB should put him in a more natural position going forward as a right footed player, it has never seemed he's quite as comfortable in attacking positions from the right as he is cutting in from the left. Defensively, he has seemed perhaps a little more solid on the right than on the left, although it could be easily explained by the timing of his RB assignments and the ebbs and flows of his overall form. We'll get into Davide more in the left back preview. The other two players who could potentially figure at right back are players who should be considered to be "out of position" but could be employed at RB in an emergency.
Billed by many upon his purchase as a Cheik Tiote replacement, Anita struggled mightily in his early run outs at the DM position. He did get his Premier League feet underneath him in a stint at RB in which he looked solid and confident enough. He had played some left back for Ajax before moving to Newcastle, so the full back role is not one alien to him. His role is surely more in the middle of the park for Newcastle this year, but depending upon injury situations on the left side of the defense, he would be the first available if Davide Santon were not able to be slid across the formation.
Ryan Taylor joined Newcastle as a midfielder. He was pressed into action at left back in the 2011-12 season and did well enough in combination with Jonas before ultimately ceding the position to Davide Santon mid-season. Having been out for all of last season with a knee injury (I remember seeing the injury v. Atromitos in the Europa League playoffs very vividly...), he is somewhat a player without a role in the squad at this point. With the signing of Massadio Haïdara and the apparent preseason statement of commitment to Paul Dummet, it seems like his days at left back are through, although he wouldn't be any closer necessarily to playing at right back. Raylor is essentially the quintessential "utility-man", probably most directly replacing James Perch.