Even though not many moves have been made in this window(and a midfielder and centre back could do with being brought in) there are also players, if used correctly, who could be like new signings next season.
Rakitic - I say him as he seemed to start losing his way, but towards the end of last season he started to regain his form and has had a solid pre-season.
Sergi Roberto - He's brilliant, but needs to be playing in midfield. He could well be the answer and we all don't truly realise it. He really stepped up in important moments last season, unfortunately his talents were being sacrificed a lot over the course of the campaign due to him playing out of position. He's very versatile, but midfield is where he should be playing and all his best moments last season came from the type of attributes you'd expect from a top midfielder. He's done plenty to prove that he deserves that opportunity and I know Valverde will want to use his younger Spanish players.
Denis Suarez - He was excellent for Villarreal 2 seasons ago(his talents have been known about for sometime) and for Barcelona in glimpses when given chances last season. He has a special talent there and if he is utilised properly then I genuinely believe he can be a success at the club. He's still only 23, it's the perfect time to give him a fair crack of the whip.
Vidal - Just as he started to impress and broke into the team last year, disaster struck and he ended up with a serious injury, but he's back now and has looked solid in pre-season, as if he never sustained a serious injury in the first place. Barring he doesn't suffer any more, he will be a big plus sign next season. It would also enable Sergi Roberto to play in a more natural position to him, especially given the new signing of Semedo on top of that.
Umtiti - Last season was only his first season and while he wasn't always perfect, he did show a lot of what he's about. He seems to be the right fit for the club and I believe he can only get better.
Paco Alcacer - It took him a while to get going last season, but when he did, he scored goals and combined well with whichever 2 of the front 3 he was partnered with(all of which felt confident playing around him), this lad is certainly a more than handy option to have. It's just about using him properly, like with Sergi Roberto and Denis. All are talented players who offer plenty of squad depth.
I don't see much of a future at the club for Andre Gomes, but with all due respects to him, he did look a lot better towards the end of the season. I feel that he doesn't deserve to be ahead of the likes of Denis and Sergi Roberto(playing in midfield) in the pecking order though and this was one of Enrique's problems last season, giving him chances when others were more deserving and would have offered more. On top of that, Turan is undoubted talent and is an option if he stays, also the young Brazilian Marlon may be given an opportunity.
There is also Deulofeu. I've never felt confident in him ever being a Barcelona player for some reason, but he is certainly dangerous, has pace to burn and could be an interesting option. I also haven't heard of any talk of Munir or Samper going, so those 2 offer depth themselves if given chances. Another young option is Carles Aleñá, who is slowly starting to make appearances in the first team and has recently signed a new contract with a whopping clause. At only 19, it's always intriguing to see what these young lads can offer, especially when they play in an area where the team could do with a bit of strengthening.
There is actually a very strong squad there with a nice balance of experience and youth, it's more about finding the right formula more than anything I think. I do believe a midfielder and defender are needed, but at the same time, I don't think it would be a disaster if the only signing was a Neymar replacement(which will be a must if he leaves) as there are actually a lot of options there in midfield.