1.The fact that your club is historycally linked with the argies does not mean that in this moment Higuain and Di Maria aren't being treated badly in comparison with other players from you club. And I'm sorry, but if you give Saviola's example, you should also accept that Milito has been treated (too) good by Barca. The only argentinians with whom the club hasn't been fair are Riquelme(although the circumstances-Gaspart- had something to do with that) and Maradona(who, just as Ronaldo where kicked out because they wanted more money).
2.Mascherano is not Argentina's captain..and being a starter for either Liverpool or Arg isn't saying to much about the player in question. However, Masche played more minutes and in more important games than Higuain and he is as much of a starter as Puyol is. In the matches against you Pep preffered the players who have a connection with the club because we all know that for Puyol, Pique or Casillas a Clasico is something else then for Masche(who played all the 180 min in the Supercup). And I'm'sure that Mascherano would have preffered playing against Espanyol to that of being a starter on San Siro.
Season 2011/2012:
04/01 2012	Barcelona	H- Osasuna	Esp Cup	W 4-0
18/12 2011	Barcelona	A- Santos FC	CWC	W 0-4	On 56	0	
15/12 2011	Barcelona	A- null	CWC	W 0-4	Started	
03/12 2011	Barcelona	H- Levante	La Liga	W 5-0	Started	
29/11 2011	Barcelona	H- Rayo	La Liga	W 4-0	Started	
23/11 2011	Barcelona	A- Milan	UCL	W 2-3	Started	
06/11 2011	Barcelona	A- Athletic	La Liga	D 2-2	Started	
29/10 2011	Barcelona	H- Mallorca	La Liga	W 5-0	Started	
25/10 2011	Barcelona	A- Granada	La Liga	W 0-1	Started	
22/10 2011	Barcelona	H- Sevilla	La Liga	D 0-0	Started	
19/10 2011	Barcelona	H- V Plzen	UCL	W 2-0	Started	
02/10 2011	Barcelona	A- Sporting	La Liga	W 0-1	Started	
28/09 2011	Barcelona	A- BATE Borisov	UCL	W 0-5	Started	
24/09 2011	Barcelona	H- Atlético	La Liga	W 5-0	Started	
21/09 2011	Barcelona	A- Valencia	La Liga	D 2-2	Started
17/09 2011	Barcelona	H- Osasuna	La Liga	W 8-0	Started
13/09 2011	Barcelona	H- Milan	UCL	D 2-2	Started	
29/08 2011	Barcelona	H- Villarreal	La Liga	W 5-0	Started	
26/08 2011	Barcelona	H- FC Porto	Super C	W 2-0	Started	
17/08 2011	Barcelona	H- Real Madrid	Sup Cup	3-2	Started	
14/08 2011	Barcelona	A- Real Madrid	Sup Cup	D 2-2	Started	
So appart from the 2 derbies, Masche also missed the games against Getafe, Zaragoza, Sociedad, Racing and Plzen. Like I said, he was treated so badly that I'm sure that in this moment he is thinking to submit a transfer request.
3. Higuain's 2011/2012 season
Started:
10/01 2012	Real Madrid	A- Málaga	Esp Cup	W 0-1	Off 69 min	
07/01 2012	Real Madrid	H- Granada	La Liga	W 5-1	Off 82 min	
03/01 2012	Real Madrid	H- Málaga	Esp Cup	W 3-2	Started
13/12 2011	Real Madrid	A- Ponferradina	Esp Cup	W 0-2	Started
07/12 2011	Real Madrid	A- Ajax	UCL	W 0-3	Started	
03/12 2011	Real Madrid	A- Sporting	La Liga	W 0-3	Off 75 min		
22/11 2011	Real Madrid	H- D Zagreb	UCL	W 6-2	Started
06/11 2011	Real Madrid	H- Osasuna	La Liga	W 7-1	Started	
29/10 2011	Real Madrid	A- R Sociedad	La Liga	W 0-1	Off 81 min	
22/10 2011	Real Madrid	A- Málaga	La Liga	W 0-4	Off 69 min	
15/10 2011	Real Madrid	H- Betis	La Liga	W 4-1	Started	
02/10 2011	Real Madrid	A- Espanyol	La Liga	W 0-4	Started	
24/09 2011	Real Madrid	H- Rayo	La Liga	W 6-2	Off 58 min	
Came as a substitute:
10/12 2011	Real Madrid	H- Barcelona	La Liga	L 1-3	On 67	
26/11 2011	Real Madrid	H- Atlético	La Liga	W 4-1	On 61		
19/11 2011	Real Madrid	A- Valencia	La Liga	W 2-3	On 72
02/11 2011	Real Madrid	A- Lyon	UCL	W 0-2	On 70	
26/10 2011	Real Madrid	H- Villarreal	La Liga	W 3-0	On 74
18/10 2011	Real Madrid	H- Lyon	UCL	W 4-0	On 71	
27/09 2011	Real Madrid	H- Ajax	UCL	W 3-0	On 74	
21/09 2011	Real Madrid	A- Racing	La Liga	D 0-0	On 67	
18/09 2011	Real Madrid	A- Levante	La Liga	L 1-0	On 58	
14/09 2011	Real Madrid	A- D Zagreb	UCL	W 0-1	On 77
10/09 2011	Real Madrid	H- Getafe	La Liga	W 4-2	On 86	
28/08 2011	Real Madrid	A- R Zaragoza	La Liga	W 0-6	On 75
17/08 2011	Real Madrid	A- Barcelona	Sup Cup	3-2	On 63	
14/08 2011	Real Madrid	H- Barcelona	Sup Cup	D 2-2	On 80	
17/12 2011	Real Madrid	A- Sevilla	La Liga	W 2-6	Unused Substitute
Like you can see, Higuain didn't start ONE important match for you. If these aren't the stats of a sub(an important one, but still a sub), I don't know which are. I don't care how you treat him, but it seems a bit far fetched to compare him with Mascherano. Maybe Pedro would be a better idea.
4. Messi didn't spoke catalan when FCB decided to help 11 years ago, just like he doesn't speak it now(although I saw some catalans on a forum who were wishing to see Messi saying more then 2 words in catalan). And you're delusional if you believe that Guardiola or the club treats Messi better because he can say "Bon dia" or "Visca Catalunya"..another fun fact is that your own club has forbidden Cristiano to speak another language than spanish while he is in Spain(so I don't know who is close minded in this whole debate). And if its a player in our current squad who learnt catalan(without beeing forced), that is Iniesta..Yaya used to speak in catalan also.
In conclusion, Messi can do all he wants because of this: