Wakefield Trinity's win at Widnes Vikings on Friday night means Saints cannot finish in the top four at the end of the regular season and, therefore, will have just three home matches in the Super 8s.
However, Holbrook says his side are already in play-off mode as they prepare to host Catalans Dragons on Sunday in the penultimate round before the split and he has not given up hope of claiming a semi-final spot in the Super 8s.
"The Super 8s started for us a couple of weeks back in effect," said Holbrook, who took over from Keiron Cunningham at the Dacia Magic Weekend in May. "We needed a win last week, that was obvious, and now we have to continue that and chase those above us.
"It is an exciting time of the year and we have put ourselves in a position to be able to do that.
"I always said we would continue to improve and get better as a side. The forward pack is going well and now the strike players are doing well on the outside.
"We are heading in the right direction at the right time of the year."
St Helens face a Catalans side already condemned to the Qualifiers with two games to spare but Holbrook is urging his players not to underestimate their French visitors.
"Catalans are hard to predict," he said. "They held Wigan at 10-10 with three guys suspended and those players will come back in this week.
"Recent weeks show they are improving. We have to be aware of them but be aware of our performance too.
"We have been playing well for a few weeks now and consistency is what is needed for us to catch the top four."
Holbrook welcomes back skipper Jon Wilkin from suspension while Catalans are poised to give a debut to winger Lewis Tierney following his arrival on loan from Wigan Warriors, while prop Romain Navarrete begins his second stint with the club.
In addition, Dragons coach Steve McNamara has winger Fouad Yaha and loose forward Greg Bird back from suspension and scrum-half Richie Myler is set to return after missing the defeat by Wigan with a shoulder injury.
Last time out against Catalan we saw THIS! 😍 https://t.co/j9xIAJls4w— St.Helens R.F.C. (@Saints1890) July 14, 2017
Myler is leaving the Perpignan club at the end of the season after agreeing a three-year contract with Leeds Rhinos before the arrival of McNamara, who must plan ahead for 2018 while at the same time ensuring his side win enough games in the Qualifiers to avoid the dreaded Million Pound Game.
McNamara can call on promising half-back Lucas Albert but is more likely to bring in an outside replacement for Myler.
"We need to find a replacement and we've got a couple of young boys in the system who may become options," McNamara said. "We've started looking at our roster and playing group for next season.
"I fully understand Richie's situation but he's a very committed player and hopefully he's going to be great for us for the rest of the season."
Long-serving threequarter Vincent Duport goes into Sunday's game needing two more tries to draw level with Clint Greenshields as the Catalan club's all-time leading tryscorer.
Duport has touched down 84 times in 181 games for the club, while Greenshields scored 86 tries in 146 appearances from 2007-12.