Carlisle Utd 1 Blackpool 4: It can be assumed that the drug testers who visited the Carlisle United dressing room after Saturday's game found nothing performance-enhancing in the samples they collected.

For there had not been much on offer, over 90 cold and flawed minutes, on which the faithful could get high. Instead it was a low day, the worst of United's season, and now a promotion push lacking consistent momentum needs another fix tomorrow night.

Doncaster, the leaders, will be licking their lips after studying footage of this undressing at the hands of Blackpool: 14th at start of play and winless since Boxing Day. Carlisle were so off the boil they made Gary Bowyer's mid-table team, rather than Donny, seem the elite of their division.

The good news after a couple of doom-laden days is that Jamie Proctor now returns from suspension. Yet the loan No9 need not be invested with talisman qualities just yet. He would not have transformed this overall no-show on his own and there needs to be a collective improvement, not a reliance on a single sharp-shooter.

Such is the madness of League Two that you would not put it past United to jerk up their standards and beat the best in the fourth tier tomorrow. Yet if they bring Saturday's performance back onto Brunton Park they will surely be dispatched. Blackpool showed the way in pressing the Blues first into uncertainty and then into some dreadful errors.

"Those mistakes got punished, but they're very easy to eradicate," said Keith Curle. Carlisle's manager also deemed the defeat "a slap in the face" and the product of some "pathetic defending"; his description of Blackpool's fourth goal.

One hopes he finds the right diagnosis, for United are still enviably placed with 16 games to go, and it would be awful to see them overhauled as a result of problems too ingrained to correct. Defensively they are still nowhere near tight enough and while this was just a fourth loss all season in League Two, the fact is they have now had more 4-1 defeats than wins in 2017.

Their winter form, featuring several draws, has kept them above the play-off line, just about. Proctor and the other new faces will now need to click and the temporary left-sided defensive issue (Danny Grainger is still two or three weeks away) must also be better solved in order to hold that position through a very demanding run of games against fellow contenders.

This, overall, felt like a defeat from a past, worse era. That it was a rarity is a tribute to United's good work for much of 2016/17. But old lapses that seemed to have been shoved in their box came back out on a drizzly day: a couple of gift goals, and the achingly predictable sight of an ex-player coming back to score against them.

Brad Potts upset a number of home supporters for the way he celebrated his 33rd minute goal. But the debate over his gestures to the Warwick Road End and knee-slide in front of the Pioneer Stand shouldn't mask the truth of that first half and indeed the second: his Blackpool were superior, more coherent, and worth every scrap of the result.

Increasingly bossing possession, and enjoying the wide space on David Mitchell's well-maintained pitch, they were more in tune with their shape than Carlisle in their 3-5-2. A lively start might have seen goals at either end, Gary Liddle twice intercepting for United and Jamie Devitt missing a golden chance at the other end, but as things went on it became clear the Blues were struggling for any fluency.

Kyle Vassell, who had an early goal disallowed for offside, was a key part of their pressing game, while Potts burst past Macaulay Gillesphey a couple of unsettling times. The former United youth player had fielded a few boos but also some applause during the warm-ups and, as the game unfolded, there were occasional signs of his strength and drive from attacking midfield.

Shaun Miller, recalled up front, made a couple of clever turns but Blackpool's defence was sturdy, full debutant George Waring also struggling to gain any serious advantage. For the visitors, Nathan Delfouneso shot greedily when a pass to Kelvin Mellor would have served him better.

As the travelling fans worked through their familiar anti-Oyston repertoire, Owen expressionless in sunglasses and hat in the directors' seats, a surge of orange attacking proved enough for the lead. Colin Daniel's work down the left was enough to beat Tom Miller, and Potts ghosted behind Delfouneso to bury a good midfielder's goal.

Potts, who was booed heavily in the corresponding game last September, certainly took his chance to offer a bit back with his celebration. His popularity rating duly went down further, but Carlisle's quality didn't rise. Waring headed a Devitt cross over the bar but Nicky Adams, the chief creator, struggled to impose himself enough close to the Blackpool box, often switching sides with John O'Sullivan and coming very deep at times to collect the ball.

One threaded Devitt pass almost found Miller, but Carlisle's slapdash half ended with a Vassell headed miss and then a sloppy throw-in by Gillesphey - sliced out of play after Luke Joyce had stretched to return it - that seemed to sum up the general tone.

Curle made a couple of urgent changes - Mike Jones and Jabo Ibehre replacing the Millers - but United were not immediately improved. Jordan Flores was much brighter in Blackpool's midfield and after testing Gillespie from 25 yards, he then scored the second, drilling through Carlisle's keeper after Joyce had faltered facing his own goal and been pickpocketed by Vassell.

Joyce has made few such errors this campaign, so this was surely the result of United's collective unease. Potts then took his leave on the hour, after staying down with an injury, and Flores almost added a third as fans in the Main Stand commented critically on what they felt was Blackpool's greater "desire".

A United fightback never truly seemed on. One then almost came out of nowhere when Liddle's floated cross was put away by Ibehre. The big substitute then nearly bustled in for another, and temporarily United seemed in the mood to change the entire direction of the previous 69 minutes.

A false dawn it was, though, for the normally unflappable Liddle then gifted Sanmi Odelusi a Blackpool third with a tame backpass. Three minutes later, Bowyer's side punched another hole in the brittle defence as Vassell fed Delfouneso to finish from the left.

Scores of fans got up and left at this point, and while Curle later used some understandably scathing words about United's defending - also pausing to blast the way the (routine) drugs testers interrupted his post-match debrief - he then became surely the first manager this term to use some Rag N Bone Man lyrics to interpret his side's errors ("I'm only human, after all…").

It was, it seemed, his way of saying there are errors even in the best of men, and not to lose all faith as a result. "There's going to be twists and turns, and some slaps in the face, but there's likely going to be some kisses on the cheek as well," Curle also said, eyeing the run-in. Over to him, now, to make United much more alluring on Valentine's night.