As Unai Emery has admitted himself, we have arrived at a "big, important moment for the season".
Having come through one test in beating BATE Borisov to reach the last 16 of the Europa League, we return to domestic matters with the two home fixtures in the space of three days.
First up is Southampton, rejuvenated under Ralph Hasenhuttl, as we seek to avenge December's 3-2 defeat on the south coast - a result that ended our 22-match unbeaten run.
We may have been second best in that game but our record against the Saints at home should give us cause for optimism: we are, after all, unbeaten in our last 23 games against them in north London.
Bournemouth and then the north London derby may be on the horizon too over the next week, but with the race for the top four as close as it is, we cannot afford any mis-steps or stalling of momentum this Sunday.
Read on for our comprehensive preview, including Emery's thoughts on the game, the latest team news, stats, and analysis of the opposition.
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