Both sides narrowly avoided relegation last season and will be looking for a vast improvement this time around.
It has been a summer of change for Betis on the back of a disappointing 2019-20 season that ended with them down in 15th place, five points above the relegation zone.
Betis have enjoyed a positive pre-season campaign, winning all three of their matches against Cadiz, Almeria and Granada.
However, Los Verdiblancos have lost their opening La Liga game in each of the last four seasons, with their last such win coming in August 2012.
That bodes well for opponents Alaves, who accrued ever fewer points in last season's elongated La Liga campaign, finishing three points above the dropzone.
Pablo Machin's side, in stark contrast to Betis, failed to win any of their three summer friendlies, losing to Huesca and Osasuna before drawing 2-2 with Real Sociedad.
None of that really matters, of course, and Alaves have a good opening-day record at home, going four games without defeat on matchday one in La Liga - a run which stretches all the way back to 1931.
Furthermore, the Babazorros are unbeaten in their last four La Liga games against Betis - their longest unbeaten run against them in the top flight.
There has not been a great deal of incoming activity at Alaves so far this summer, but newly-appointed Machin will be confident of keeping his side in the division.
A fast start to his tenure will help to achieve that target, but Machin is winless in all four home league meetings with Sunday's opponents, drawing two and losing two.
Alaves pre-season form: LLD
Real Betis pre-season form: WWW
Alaves are winless in their last four home league games, failing to score in all of them, so there will be extra pressure on the attacking players to click into gear.
As for the visitors, Pellegrini's immediate priority is to tighten up a leaky defence, with the addition of experienced goalkeeper Bravo considered a big coup.
Borja Iglesias struggled in his debut campaign with Betis but, given the lack of other real options, he is expected to be selected up top.
Loren Moron has scored three La Liga goals against Alaves - more than he has managed against any other opponent in the competition - and is another option in the forward line.
Alaves possible starting lineup:
Pacheco; Ely, Laguardia, Duarte; Mendez, Pina, Battaglia, Pons, Rioja; Joselu, Perez
Real Betis possible starting lineup:
Bravo; Emerson, Mandi, Bartra, Moreno; Guardado, Rodriguez; Fekir, Canales, Joaquin; Borja
We say: Alaves 1-2 Real Betis
Betis enjoyed a positive pre-season campaign and look rejuvenated following the arrival of Pellegrini. The visitors have won just one of their last five games at Mendizorroza, but we are backing them to take all three points this weekend.