The Bulls fought back from 24-8 down to beat Hull KR last weekend, but the former Wakefield man doesn’t want slow starts to become a habit.
Speaking in his blog on the official club website, Jeffries said: “We stated very poorly and it is something we have spoken about this week. We can’t afford to start like that otherwise we are going to kop some hidings.
“We managed to get back into the Hull KR game but it’s not something we want to be doing every week because it‘s not going to happen. If we start like that this week we will get our backsides kicked so we know we must do better.”
Jason Crookes scored a hat-trick as Bradford scored 28 unanswered points in the last half hour to pick up their third win of the season.
In round four against Wakefield, the Bulls conceded a try inside the first minute, before eventually easing to a 36-18 victory.
They are live on SKY Sports for the fourth consecutive week on Saturday, when St Helens travel to Odsal, looking to end a run of four games without a win.
Jeffries added: “Saints have had a bad run but believe me they are a quality side.
“They have a great pair of young half backs that are in the England Squad and they have quality all over the park, with such as Tony Puletua and Lance Hohaia running the show but if we can keep improving a little every week I think we should be OK.”