Manchester United have overcome a very poor start to life under new manager Louis van Gaal to comfortably establish themselves in third place in the Premier League. However, they are still some distance from both Chelsea and Manchester City and have plenty of work to do before they are ready to compete for football's biggest prizes again.

Given last season's nightmare and the number of injuries suffered during the current campaign, United can be happy with their improvement so far, but with stars like Angel Di Maria, Radamel Falcao, Wayne Rooney and Juan Mata in their ranks, Van Gaal's men should be setting their sights high.

What they need:

United spent more than £150m signing Ander Herrera, Luke Shaw, Marcos Rojo, Angel Di Maria, Daley Blind, and Radamel Falcao (on loan) during the summer.

However van Gaal failed to finish the job properly with a top centre-back to cope with the departure of both Rio Ferdinand and Nemanja Vidic.

Who could join:

United have recently been linked with Aston Villa's Ron Vlaar and West Ham defender Winston Reid. Both players would add give Van Gaal more options and provide a solid presence in back-line. However, the real target should be to finally fill the void left by Ferdinand and Vidic and sign a genuine world class leader.

However in this area the market looks particularly dry, especially in January. Atletico Madrid's Diego Godin or Borussia Dormund's Mats Hummels would both be excellent additions, but whether United could lure them from their current clubs is a different story altogether.

Some may think United also need a central midfielder like long-term target Kevin Strootman or Arturo Vidal, but with Michael Carrick, Daley Blind and Ander Herrera on the staff, and Rooney excelling in a deeper role, they can realistically wait until next summer to focus now on the defence – especially given that Van Gaal is playing with three centre-backs.

Furthermore a consistent right-back to play ahead of Antonio Valencia and Rafael may also be added should the opportunity arise. Indeed United have recently been linked with Everton´s Seamus Coleman, one of the top practitioners in this area.

Victor Valdes may also complete his permanent move to Old Trafford once he complete his injury recovery.

Who could leave:

Anderson is expected to leave the club this January on a permanent basis after failing to make the impact expected since his £20m arrival in 2007. A return to Brazil is the most likely option.

Furthermore, Van Gaal may consider sending Adnan Januzaj out on loan to earn more playing time and complete his development. David Moyes seems likely to reunited with him at Real Sociedad.

Should Valdes finally complete his move to United, Anders Lindegaard will have to look for opportunities elsewhere.

What the manager has said:

Van Gaal has distanced himself from further big spending in the January transfer window, saying: "I think it is disgusting, always writing about numbers. I don't think that Ed Woodward said anything about it, I don't think I have.

"I think it's disrespectful to my players. I don't talk about it. I believe in the players. That is my answer."