Manchester United are looking into the possibility of signing Porto right-back Danilo da Silva, [football] direct news understands.The Brazilian defender has been one of the club’s most impressive performers in recent times, which has led to reported interest from Spanish giants Real Madrid ahead of the summer transfer window.This in turn has led to speculation that United could look to snap up current Real full-back Daniel Carvajal, also a target for Arsenal and Inter Milan, though it has now emerged that the Red Devils could rival the Bernabeu outfit for Danilo instead.The 22-year-old has been with the Portuguese giants since 2012, after he first caught the eye in his native Brazil with Santos.One of many players brought in by Porto on the cheap from South America, he could now be in a long list of big names heading out of the club at the end of the season, with speculation over the futures of the likes of Jackson Martinez, Eliaquim Mangala and Fernando as well.United are currently unconvinced by their options at right-back, with none of Rafael, Chris Smalling or Phil Jones truly excelling in that position this season.Watch Manchester United v Manchester City Tuesday night. 24 hour Sky Sports Day pass for only 9.99. No contract.