The Seagulls let slip a second-half lead to go down 2-1 to Spurs in their final WSL game of the season.
They were rarely at their fluent best in front of almost 7,000 fans and saw their seven-game unbeaten run come to an end.
Albion face Manchester City at Wembley in the cup final on May 31.
Head coach Vidosic said: “It wasn’t the most enjoyable game, if I’m honest. We looked a little bit off.
“I think it is a difficult one sometimes because, as much as we don’t want to talk about it, it’s definitely in the back of everyone’s minds with the cup final.
“If anything goes wrong today or you get injured, then you’re out.
“Being a former player, I understand that as well.
“You sort of feel like there is this game after. That’s huge.
“But we wanted to be better and we wanted to use this as a preparation for that.”
Vidosic named the same outfield line-up as started the cup semi-final at Liverpool but brought in Sophie Baggaley for Chiamaka Nnadozie in goal.
He said: “She’s one that’s also deserved it.
“It’s a lot harder throughout the season to make a change for a goalkeeper during a game.
“She has been doing fantastically well.
“Chi has just had a little niggle that we wanted to look after as well.”
Vidosic took off defender Cailin Hayes when she was on a yellow card and also substituted Fran Kirby and top-scorer Kiko Seike.
He said: “We didn’t want to take any risks.
“On another day, it’s maybe a little bit of a different outcome, but I think in general it just wasn’t a performance where our levels usually are.”