Long was instrumental in the Saints' recent 4-2 thumping of Manchester City, scoring the opening goal and giving a laboured City defence a torrid time throughout the game with his tireless running and intelligent movement.
Saints exorcise City ghosts with big win
Prior to the game, the Champions League semi-finalists had been one of only two teams that Southampton had failed to pick up the full three points against since manager Ronald Koeman joined the club in the summer of 2014.
The other team to remain unbeaten against the Saints since then are Spurs, who play host as the two sides face off in the penultimate weekend of the current Premier League campaign.
One hurdle down, one to go
Speaking with Southampton's official YouTube channel, Long said that Koeman had made a point of their recent record against City and Spurs, with the Irishman now describing City as "one hurdle over".
Talking of the need to go to White Hart Lane and repeat the same result this weekend, Long claimed that the squad is "very confident", though he admitted that things "don't get any easier now" at the business end of the campaign.
"It's another tough game for us", he went on, "but we're playing good football". The 29-year-old said he was looking forward to "a hard week's training", after which he believes Koeman will have a clear picture of what his side need to do to turn over second-placed Spurs in their own stadium.
Spurs hope to bounce back from title knockout
There may be no better time to face the North London side, with the players likely to be deflated after their 2-2 draw with Chelsea on Monday night which mathematically secured the title for Leicester City.
Spurs needed three points to stay in the race for top spot and were leading 2-0 at half-time, but they seemed to lose their nerve as the Blues improved in the second half and Eden Hazard's stunning late equaliser proved the knockout blow in a tempestuous last 20 minutes.
The mood in the two camps is likely to be markedly different, therefore, despite Spurs confirming their place in the Champions League for next season.
With two games to play, Southampton are still on the hunt for Europa League qualification but their fate is not wholly in their own hands just yet.