The Swiss defender has joined the Primera Division side for an undisclosed feel, while the 20-year-old Brazilian attacker has arrived at Mestalla on a free transfer
Swiss international Senderos arrives at Mestalla from Fulham on a permanent deal for an undisclosed fee, while Araujo, a 20-year-old striker, has joined Los Che from Brazilian outfit Cruzeiro on a free transfer.
Banega, though, is returning to his native Argentina to spend the rest of the season with Newell's Old Boys.
Former Arsenal defender Senderos had loan spells with AC Milan and Everton while still at the Emirates Stadium, before moving to Fulham in 2010.
"The club would like to thank Philippe for his service and wish him well for the future," read a Cottagers statement.
Senderos and Araujo are not the only new faces at Mestalla this week. Earlier on Friday they sold Sergio Canales to fellow La Liga outfit Real Sociedad, one day after announcing the arrival of Seydou Keita from Dalian Aerbin.