That photo is from the friendly against Spurs that was the official opening of the Amex. Must have been quick to take it as he was only on for the last min or so.
https://www.brightonandhovealbion.com/galleries/1272301/when-albion-met-spurs-to-open-the-amex
I don't remember another Sanchez, you could mean David Gonzalez? Awful keeper who had somehow spent about 4 years at Man City who we picked up after they terminated his contract.
Played twice for us (wiki has him listed as making 4 appearances but I'm sure he only played 2 games), a 2-2 home...
According to this he made the bench a couple of times but never played.
https://www.transfermarkt.com/chris-jones/leistungsdaten/spieler/262194/plus/0?saison=2001