Even if it ends with a league-and-cup double, there will be some who feel disappointed by Barcelona's season.

They blew the chance to win the "double treble," which would have made this team truly historic and remembered forever.

That doesn't mean they have been bad by any means—just not quite as good as they were the year before.

Some of their players lost their way a little bit, and others arrived but didn't live up to expectations.

Here are the five Barcelona players whose stock dropped this season.

5. Neymar

In January, Neymar was flying. On the Ballon d'Or podium for the first time, he was having the time of his life.

But after he returned, the Brazilian's performance level started to decline. He was scoring fewer goals, getting fewer assists and, worst of all, his overall contribution dropped.

As Andres Iniesta has demonstrated throughout his career, you don't need to score or assist to be a great player in an attacking sense, but you do need to be consistent and always a positive for the team.

In some weeks in the second half of the season, Neymar looked listless. At other times, selfish. Sometimes, he was just unlucky.

Things picked up a little for him toward the end. After five games in which he failed to contribute much of note, he struck against Deportivo La Coruna and then again against Sporting Gijon.

With a long rest period before the Olympic Games in Brazil this summer, Barcelona will hope the player can revitalise himself, ready to come back refreshed next season.

4. Aleix Vidal

Aleix Vidal was signed at the end of last season, when it was still unknown whether Dani Alves would extend his deal with Barcelona that was set to expire in the summer.

Barcelona knew he couldn’t feature until January because of their FIFA-imposed transfer ban, but they were hoping he could come in and play an important role between then and the end of the season.

Unfortunately, it’s been a virtual nonstarter. Vidal has been picked in six games in La Liga and featured in three more as a substitute, as well as five Copa del Rey clashes.

He has not won Luis Enrique’s trust, with some shaky defensive performances, meaning Alves—despite not being anywhere near his best—has been the only viable option in his position.

According to Sport’s Lluis Miguelsanz, he has also shown a lack of determination, although that is something he is willing to work on:

After finally being registered in January, Aleix Vidal had an important role, but his participation has diluted. And it all has an explanation: The coaches feel he's shown a lack of competitiveness when he's had a chance and that he can do a lot better than he's been doing.

...

The player knows to what he owes this situation and he understands he must improve. To play for Barca comes with a price and Luis Enrique has clearly shown him the path. Improve his levels or he will no get minutes in a Barça shirt. Despite the fact the situation may seem tough, the coaches still have confidence in Aleix Vidal, a player that cost close to 20 million euros.

A big season awaits the former Sevilla man.

3. Marc Bartra

Marc Bartra’s stock was not particularly high at the start of the season, having failed to play much last year. But with every passing campaign he cannot force his way into the side, it reflects worse on the centre-back.

The 25-year-old started just four games in La Liga this season and is clearly not one of coach Luis Enrique’s favoured players.

Esther Blasco of Sport explained how even when he did well in the recent clash with Deportivo, he was cut from the squad for a game against Espanyol a couple of weeks later.

Only a couple of weeks ago Lucho praised Bartra for not putting down his arms despite his situation, when the defender played well and scored against Deportivo in the absence of both Pique and Mathieu. This is the sixth time he's been cut from the squad in total in La Liga, this time because Mathieu received medical clearance to play after being operated on.

Vicente del Bosque called him up to the Spain squad for Euro 2016, but that seems more to do with the coach’s habit of selecting the men he relies upon than anything Bartra has done to merit it.

That’s not necessarily his fault—he hasn’t had many chances, even when he has been worthy. Perhaps the writing was on the wall when Luis Enrique signed Thomas Vermaelen and Jeremy Mathieu in 2014.

2. Jordi Alba

Jordi Alba has not been at his best this season.

The left-back hasn’t attacked with the same verve he did last year, less precise than ever it seems in attacking areas.

And at the back, he has been caught short a few times too—the full-back spots have been Barcelona’s weakest positions this season.

Per Sport (link contains profanity), Neymar swore at the defender during a recent game, something for which the Brazilian was criticised.

While it may not be the best way to dispute anything with a team-mate, Neymar’s frustration with Alba probably related to more than just one match.

Barcelona would do well to sign a left-back in the summer to put pressure on Alba and make him fight for his place in the team.

1. Arda Turan

Arda Turan seemed like he would be a good signing on many levels when he arrived last summer.

Barcelona were getting a world-class player, and rivals Atletico Madrid were losing one.

Arda is versatile, able to in either of the two wide attacking positions or the two midfield roles behind the front three.

But he simply hasn't sparked at the club. Sitting out six months while Barcelona served the rest of their transfer ban probably didn't help.

Arda seems to have clicked on personal terms with the other players, often featuring in Instagram snaps with his team-mates. However, when it comes to football, he seems on a different wavelength.

The Turk is an intelligent player, but that has not manifested itself in his integration with the brilliant creativity of the attacking trident of Lionel Messi, Luis Suarez and Neymar.

Of all the players in Barcelona's 2015/16 squad, his stock dropped the most. There are even some at the club who think he should be sold, per Sport, although manager Luis Enrique is not one of them.