The Championship leaders thrashed the Saints 5-0 and are now just one win away from a return to the Premier League.
Martin’s team are now set for a fourth-placed finish, unable to be caught by fifth-placed West Brom and unlikely to catch Ipswich Town who are five points ahead with a game in hand.
Saints have a home game against 17th-placed Stoke City on Saturday before travelling to face Leeds on the final day of the regular season.
I expect a reaction on Saturday, Martin told BBC Radio Solent.
It will hurt more than you know losing like that but there will always been bumps in the road, it’s part and parcel of football.
Martin’s side have struggled in recent weeks, winning just five of their past 10 games, and struggling to capitalise on the top three dropping points in the race for automatic promotion.
The final two games offer an opportunity to gain some momentum ahead of their play-off semi final.
