Chelsea and Manchester United are also in the hunt and, with all four clubs separated by three points, Pochettino said their primary focus was on the battle for the top four and not on their first European Cup semi-final since 1962.
"We are not thinking of Ajax," Pochettino told reporters. "We showed at Manchester City that we're thinking in the 'today' and that competition, the Premier League.
"Now our energy is in Brighton. It's so clear that we have two objectives, one is to be in the top four at the end of the season and the other is to beat Ajax.
"But we need to go step-by-step, the players know it. I think the behaviour and the mentality is perfect."
Pochettino, already missing injured striker Harry Kane, will also be without central midfielders Moussa Sissoko and Harry Winks. Both players suffered groin injuries and are doubtful for the first leg of the semi-final at White Hart Lane next Tuesday.
"Moussa Sissoko is not going to be fit, maybe for the next two weeks," Pochettino said. "We hope he can recover before but I'm not so optimistic.
"Harry Winks, we don't know because it's a problem that is one day very good, next day not very good. It's about assessing each day, we hope he'll be available for Tuesday but we're not sure."
However, Pochettino was bullish on goalkeeper Hugo Lloris's return after the Frenchman missed the league game at City with a muscle injury.
"Lloris, I hope yes, we are going to assess," Pochettino added. "We have a training session and we hope it's not a big issue, we hope he's going to be available."
(Reporting by Rohith Nair in Bengaluru, editing by Ed Osmond)
