I saw Enes Ünal a number of times when he was at Villareal--looked fairly dangerous. Villareal seems to have liked him more than Christian Espinoza. Sandro got on the field occasionally when he was at Barcelona and was a reasonable threat.
". . . I'm smiling and I'm happy 'cause there is a game today . . ." -- San Jose Ultras Too self-referential?
Real Valladolid squad: https://www.transfermarkt.com/real-valladolid/kader/verein/366 If I counted correctly they have 18 players that would be considered 'true dps' in MLS (i.e. making 1.5m or more). Their two top paid players Alcarez and Calero (each making 10m euros) would be the highest salaried players if they were in MLS (beating Zlatan's 7m usd). Is there any way to find out which real valladolid players will be available for tonight so that we can learn about them before the game?
The values you stated do not represent their salaries but rather the player's transfer values in the open market. There's no way that a low-tier La Liga club could afford to pay one player a 10m euro salary let alone two players. For reference, Real Betis, the 10th place finisher in La Liga last season had an average player salary of $1.7m and they're at leat a tier above Valladolid in terms of financial standing and prestige.
"LIVESTREAM: Quakes vs. Real Valladolid C.F. | 7:15 p.m. | July 16, 2019" (SJEarthquakes.com - Monday, 7/15/19) GO SAN JOSE EARTHQUAKES!!! -G
I dislike the quasi-religious aspects of that image. A lot of pro footballers already have a 'healthy' self-regard and don't need any encouragement of that sort...
The real comparison is squad value: ~82mil versus ~18mil. So their players are valued at 4x of ours. Some of squad value is related to nationality which affects the ability to work or squad nationality preferences/rules on nationality, so you can't just line them up side by side. But I think in this case that isn't a major consideration and that is probably pretty accurate. As for friendly roster info, you aren't likely to find it. Even for major Euro clubs, pre-season friendlies have almost zero information. You'll get some vague summary after the game from a club-friendly news source that will only mention the performance of individual players, nothing about the game itself unless something crazy happens.