However, the rest of the squad's injured players remain sidelined for the visit of the league leaders.
The manager also confirmed that Victor Valdes is training with the squad.
Read what else he discussed below:
3.47pmGood afternoon! Manchester United host Chelsea in the Premier League this weekend, looking to bounce back after dropping points against West Brom earlier this week.
3.50pmVan Gaal has been hit by injuries at this start of this season, but has been boosted by the return of a string of players in recent weeks. He should be updating us on the team's absentees this afternoon.
3.52pmIt's a special day for the club's captain today...
3.55pmVan Gaal may face questions about Victor Valdes this afternoon. The former Barcelona goalkeeper, who is a free agent, is understood to be training with a view to signing a contract with the club.
3.57pmFormer Chelsea midfielder Juan Mata has been preparing to face his former club:
3.59pmAs with all Premier League fixtures, we'll have live coverage from this match from an hour before kickoff, as well as team news, reaction, player ratings and tons more.
4.01pmRight then, Van Gaal is ready to speak to the media...
4.02pmStarting with Valdes, Van Gaal tells reporters: "It is not a surprise because I have done it with lots of players. I have a relationship with a lot of them. I gave Ronald de Boer and Edgar Davids training possibilities in the past - Valdes is one of these players. Robin van Persie also. When he played for me in the Dutch squad, I allowed him to use our medical department to keep fit for the World Cup. I wasn't the manager of United at the time, so I have always done it."
4.03pmMoving onto his current squad, Van Gaal provides an update on his injured players: "Ander Herrera was already fit and Di Maria said after the game that it wasn't so heavy and it's not. It was only the first day he didn't train, so it's no problem. I'm sorry to say no other players are back, even if I let Carrick play in London for reserves because he needs to play matches when you are five months injured. He told me it was his first game for the reserves.
4.04pmTurning his attention to the opponents, Van Gaal admits: "Chelsea are one of the top teams, as are Manchester City at the moment. Jose has worked more than a year with his team and last year didn't win anything. You have to build up. They are playing like a team and we have to as well, but to play for 90 minutes. We played as a team against West Bromwich Albion but made individual errors.
4.06pmDespite Mourinho saying that there is little chance of Diego Costa playing for Chelsea, Van Gaal believes that he will feature: "He will play with him when he can because Jose wants to win. He's scored nine goals in seven games, which is remarkable. So he's in good shape but he was ill so you never know."
4.08pmReflecting on his time working with Mourinho, Van Gaal tells reporters: "He has said that and it's remarkable because not many people talk about that. He says it not only about Louis van Gaal but Bobby Robson. I appreciate it but you always do it by yourself. I was also an assistant coach and my eyes were also opened and it's good that his eyes were open when he was my assistant, but you do it by yourself. He's a wonderful coach and to see him as a coach winning trophies in other countries is fantastic."
4.10pmVan Gaal is asked what impresses him most about Mourinho. He responds: "That you can never imagine that he is a very modest and emotional human being, and I like that. But it's a surprise, no? He's one of the best coaches in the world."
4.13pmVan Gaal is asked about Valdes again. For the time being, the goalkeeper is just training with United to regain his fitness, but when asked about the prospect of signing him, Van Gaal confirms: "United always have their eyes open."
4.16pmThat's all from Van Gaal today, but join us again on Sunday to find out if United can end Chelsea's unbeaten start to the season. Until then, thanks for joining us this afternoon. Goodbye.