Let's address the big green and white elephant in the room, shall we?

The concession of late goals has been a blight on Celtic all season. There is no escaping that football fact. Celtic are in a fight to the finish if they are to secure another illustrious Scottish Premiership and Scottish Cup double, you best believe it. The champions' Achilles heel will make the next six games as we countdown to the end of the current campaign a real nerve-shredder.

Brendan Rodgers' men in effect had to win the game three times on Saturday having come from behind to lead 2-1 and 3-2 only to blow it in injury time in normal time and then again in the last minute of extra time. Once was careless. Twice was bordering on football criminality. Celtic should never have been involved in a dreaded penalty shootout to get to the Scottish Cup final. End of.

What is it about Celtic this season? Why have they shown a staggering ability to concede crucial goals late on? It has cost them at critical junctures over the course of the last nine months.

READ MORE: Why Celtic's Hampden showing was akin to 'Jekyll and Hyde'

It started on matchday two against Lazio at home in the Champions League. Pedro's 95th-minute header was a sickener at Celtic Park and condemned the hosts to a heartbreaking 2-1 loss. It also mapped out the shape of Group E as Celtic found out to their cost that they were already behind the 8-ball in terms of qualification for the knockout phase or even dropping into the Europa League for finishing third in the table.

That didn't materialise. You thought Celtic might have learned a salutary lesson from that by not switching off in games. The extenuating circumstance that night allegedly was a ring-rusty Cameron Carter-Vickers returning from injury. He was robbed of possession before Matteo Guendouzi'scross was nodded back across Joe Hart and into the bottom corner by Pedro.

Rodgers said: "We're bitterly disappointed. To concede late on like we did, it's really harsh on us. But, there is learning there, you have to secure the ball in the game and if you're not going to win it at that stage, you certainly can't lose it.

"The players gave everything, we have the mentality, everything. I'm just disappointed for the players and supporters that we couldn't get the result. It was a devastating way to lose a game because we deserved something from it, but we'll analyse it and learn the lessons from it."

You could argue that lessons have not been learned. Fast forward to November and Celtic blew the chance to move 11 points clear of Rangers - although the Light Blues had two games in hand - when Jon Obika scrambled an injury-time equaliser from a corner into the danger area which the home defence failed to deal with satisfactorily. Goalkeeper Joe Hart was heavily criticised for his star jump attempt to clear the danger.

Yet Motherwell threw a simple ball into the mixer and profited from it. It was that easy. The Northern Irishman again lamented: "A draw at home always feels like a defeat. These are games I'd expect to win but you need to do it."

Celtic Way:

They were up to their old tricks again in February when David Watson headed a 92nd-minute leveller for Kilmarnock when Celtic failed to kill the game off when leading 1-0. Celtic remained top of the table by a point but Rangers held a game in hand. Argentine Alexandro Bernabei was the fall guy on this occasion as his positioning was utterly shocking and he lamely and lazily claimed a foul for a slight nudge by Watson.

At least Rodgers appeared to be showing signs of self-awareness about his team when he uttered these words: "It's the nature of how we conceded, it's not the first time. It's not a one-off, it's happened too many times. But there's still a long way to go. Every title is there to fight for, we're still there to do that. I totally get the reaction of the supporters."

Celtic Way:

It wasn't the first time and it certainly wouldn't be the last. Nope, Celtic weren't done with handing out last-minute gifts. Celtic rolled into Ibrox earlier this month and played Rangers off the park for 45 minutes and established a two-goal lead. Rangers hauled themselves back into the contest to level at 2-2 with four minutes left on the clock. Incredibly Adam Idah made it 3-2 to the visitors on 87 minutes. Cue Rabbi Matondo who bent a superb curled effort into the rigging to snatch a draw for the Light Blues in the 93rd minute.

However, South Korean Yang Hyun-Jun was accused of making a half-hearted attempt to prevent the shot and needlessly showed the Welshman inside when he ought to have forced him to go down the line. He did neither. The last-minute goal trend continued at Hampden Park in the semi-final of the Scottish Cup semi-final against Aberdeen.

A lot has been made this season about so-called patterns of assistance by referees when it comes to officiating Celtic. Celtic have certainly aided and abetted their opposition with some patterns of assistance of their own. Namely not defending and not being able to see games out in the closing minutes. That's all on Rodgers and his team. Honduran winger Luis Palma was guilty of giving away cheap possession and failing in basic game management on Saturday in Mount Florida by keeping hold of the ball. Aberdeen winger Junior Hoilett's deliveries on both occasions might well have been on the money as Ester Solkler and Angus MacDonald crashed in late-headed levellers in normal and extra time respectively.

Although Celtic right-back Alistair Johnston didn't do enough to cut off the source of the cross - twice. If you are the Celtic manager then the inquest should go on all this week as neither goalkeeper Hart nor defensive central pairing Carter-Vickers or Liam Scales or even Greg Taylor contested the ball when it was hung up in the air to the back post - twice. If ever moments were microcosmic of Celtic's season this was it - twice. Celtic lost two goals that were carbon copies of each other. Bread-and-butter crosses to the back post were not defended properly by a team trying to see it over the line and reach a cup final.

READ MORE: FOUR Celtic players that Rodgers said had 'great courage'

As Rodgers said: "It was disappointing to lose those two goals. We stuck on an extra centre-half to deal with the threat, but Junior Hoilett’s crossing was real quality. We just couldn’t see it out and if you don’t do that it can be difficult."

Celtic Way:

Celtic and Rodgers need to address their chronic defensive problem and the terrible habit of leaking late goals... and quickly. They won't be able to do it before the end of the current campaign but Rodgers has to come up with a defensive short-term fix to plug the leaks.

Will Polish star Maik Nawrocki finally get his chance to partner Carter-Vickers for the crucial six-game title and Scottish Cup run-in? Scales appears to have run his race when it comes to being the go-to guy that Celtic can rely on at the back of the pack. Bojan Miovski gave the Irishman the runaround and a torrid time at the national stadium that he was positively spooked. The Macedonian laid Scales' defensive deficiencies bare. Swedish centre-back Carl Starfelt may have got a bad rap from some of the Celtic faithful but my goodness he's morphed into Franz Beckenbauer since he left the club last summer.

Rodgers will be aware that big changes will be needed in the defensive department come the summer. It has become Celtic's priority in the transfer market once again almost 12 months on from signing £8 million worth of centre-halves in the form of Nawrocki and Swedish defender Gustaf Lagerbielke. The 51-year-old doesn't fancy either. Rodgers has to make do and work with what he has.

The major worry for Rodgers right now is that Celtic are still being plagued by the same defensive mistakes that have cost them dearly at times throughout the whole campaign. Rather like the Scottish Cup semi-final on Saturday those error-strewn displays must be of huge concern to Rodgers. Celtic simply cannot afford to continue to be a 'lastminute.com' team when it comes to shipping late goals as it could well scupper their lofty domestic double ambitions. There are some bad habits that football teams need to kick if they are to be successful.

Losing late goals falls into that category as it offers hope and encouragement to Celtic's city rivals who last week believed they were down and out in terms of the title race. Not so now. The Celtic fans had better strap themselves in for a six-game rollercoaster. The Scottish Premiership title and Scottish Cup are still very much up for grabs.

If Celtic blows the chance of a Scottish Premiership and Scottish Cup double there literally will be no case for the defence. Why? Well, largely because the players will be guilty of being repeat offenders.