The Gunners boss made eight alterations to his starting XI to take on Crystal Palace in a Carabao Cup quarter-final.
He saw his side draw 1-1 over 90 minutes before going through 8-7 on penalties at the Emirates.
After a flurry of first-half pressure failed to bring a reward, Arsenal went ahead with an unfortunate Maxence Lacroix own goal after a corner on 80 minutes.
But Marc Guehi replied, also from a set-piece, deep in added time.
Arteta brought in Riccardo Calafiori at centre-back and striker Gabriel Jesus made his first start for 345 days.
David Raya, Bukayo Saka, Martin Zubimendi, Martin Odegaard and Declan Rice were among the substitutes, as were former Albion duo Viktor Gyokeres and Leandro Trossard.
Odegaard, Saka and Trossard were sent on between the 59th and 67th minutes in pursuit of a breakthrough and Rice followed them for the closing stages..
Gabriel Martinelli, who had been creating problems on the left wing, went off injured.
Defenders Ben White and Cristhian Mosquera are both currently out with hamstring and ankle injuries respectively.
Gabriel and Piero Hincapie, who started at Everton on Sunday, were also ruled out of the cup tie with shorter-term issues.
Arsenal lead the Prem going into the weekend and will face a Seagulls side for whom Lewis Dunk, Jan Paul van Hecke, Diego Gomez and possibly Danny Welbeck will return to availability.