"We were very unlucky, we were one-nil down in the first 15 seconds so it was hard to take that," Pochettino told Sky Sports News.
"But after that we were prepared, we showed that we had good character, good personality and we did well after that. I just think it was an unlucky play, it was a very complicated match overall.
"I think the pitch was not up to par today - the wind was very strong but I'm not here to make any excuses. It was just a very tough match, a very tough day at the office and we did our best today, we showed very good character."
Pochettino's Southampton side are currently fifth in the Premier League table.