Hull have only won once in the league since the opening day of the season and a run of four consecutive defeats has seen them tumble towards the relegation zone.
Their 3-0 loss to Manchester United on Saturday saw them slip to 17th and only goal difference is keeping them above QPR and Burnley.
However, Bruce remains confident in the squad at his disposal and believes they can turn their fortunes around in the coming months, starting at Everton on Wednesday.
"For me December and January defines the season," he added. "I still haven't had my best team available, fit and ready to go yet. I hope to have that team on the pitch soon.
"I think the bottom half of the division is [in the relegation fight], there's four points separate 10-11 clubs. When it's like that we're all in it.
"I've always said we need 10 wins [to survive], at the moment we've got two so we've got some catching up to do.
"If we can get a result [at Everton] it would be terrific, we know we're capable, we have to play well and stop the silly mistakes that littered Saturday's performance.
"I am optimistic we can, and am convinced we can have a decent season."
Bruce will recall Tom Huddlestone after the 27-year-old was dropped to the bench for the defeat at Old Trafford.
Huddlestone impressed in his first campaign at the KC Stadium last season having moved from Tottenham, but he has struggled to maintain that form this term, resulting in his recent omission.
"Tom Huddlestone set really high standards here, but when you lose a bit of form you start fighting it," said Bruce. "We thought we'd take him out and tell him to have a look at it, have a break, and hopefully it'll do him the world of good.
"We all know the ability he has got, he's had a wonderful 18 months with us, it hasn't gone so well over the last couple of weeks, however I can say that about a few of them.
"Tom was unfortunate to be left out, but he took it exactly the way I expected he would, he didn't go off in a huff, he just got on with it and he's in contention again."
