Moyes took over as coach of the Basque club last month and has presided over a draw and a win in La Liga, as well as the stalemate in Oviedo which gave Sociedad a slight advantage ahead of the return in San Sebastian in two weeks.
“We knew we were playing at a very tough stadium against a team who are fighting for promotion to the second division,” Sociedad midfielder Ruben Pardo told Spanish television.
“It’s going to be a very nice match at the Anoeta and we are really looking forward to playing it,” he added.
Villarreal have one foot in the last 16 after they held on with nine men for a 2-1 success at third-tier Cadiz.
Defender Adrian Marin was shown a straight red card in the 59th minute and Israel Puerto was forced off due to injury when Villarreal had already used up their three substitutions.
Valencia, the 2008 winners, gained the upper hand over Rayo Vallecano in their first leg when they fought back from a goal down to beat their La Liga rivals 2-1 in Madrid.