ROLL on up for the Ronny Deila rollercoaster. That is the word the Norwegian chooses when asked to describe his 2015 and it seems an appropriate summation of a 12-month white knuckle ride which ends with him clinging onto the Parkhead hot seat for dear life.

From the highs of the club's fourth successive top flight title to the stomach-churning lows of a second successive failure to reach the Champions League group stages, this year has provided no shortage of twists and turns but what many of the club's supporters really crave is a chance to demonstrate some straight line progress. The final chance of the year to do that comes at Dens Park this evening.

“It has been a rollercoaster in my opinion," said Deila. "As for the positive things, we had a very positive last part of the 2014-15 season, with a double, and a couple of good games in Europe. We started well in Europe this season but got a blow against Malmo and after that we lost some players and we had to reorganise a little bit. That affected us I think especially in the defence and the results in Europe weren’t good enough. Having said that, in the league we are in a good position, we are into everything in Scotland. Sometimes it’s grey, not black or white.”

Some of the more masochistic Celtic fans might claim to have recognised fifty shades of it this season but Deila still sees much of promise as we prepare to go into 2016. The picture was perhaps skewed as the likes of Scott Brown and Charlie Mulgrew were on the long term injury list, with Kris Commons and Leigh Griffiths out also, but Deila pointed to his first XI during the 2-2 draw against Hearts that had all either been recruited or become first team regulars during his time in charge. He sees plenty of room for growth in young players such as Kieran Tierney and Tom Rogic.

“I expect that all the young players will get better," said Deila. "If you see the team on Sunday there was only one player who played before my time, Mikael Lustig, the rest are all players who came in under me or were on the bench or not in the squad. And it’s a young team. I know that you have to suffer a little bit when you play young teams but I know in the end they will affect the club and me and it will be fun. But in the beginning with young teams you need to suffer because they are a little bit up and down. But at the same time we have to win enough to win the league and hopefully win cups as well.”

Having been dumped unceremoniously out of Europe, the Parkhead side suddenly find the pressure being ramped up by Aberdeen domestically. They have dropped seven points in their last five league matches and won just two of their last seven games in all competitions, even if mitigation lies in a lengthy injury list, which has two new members after the problems sustained by Stuart Armstrong and Dedryck Boyata at Tynecastle.

It provides an opportunity for fringe players such as Efe Ambrose, Gary Mackay Steven and possibly even Scott Allan, a man who has been used so sparingly thus far that he must be pondering whether he made the right career move in August. However short or long their window of opportunity may be, Deila says the imperative is on his players to grasp it.

“They have to be ready," said the Norwegian. "And they have to take their chances. It’s so tough to play here when they have team-mates who are very good, so they have to show when they’re on the pitch that they deserve to play."

While a spiky, feisty atmosphere is always guaranteed at Dens Park, it may actually work in Celtic's favour that their next match is away from Parkhead. Playing in front of a noisy, enthusiastic band of travelling supporters often proves uplifting, while the pressure to produce in front of a larger audience can be sometimes suffocate. One of the scarier stats of Celtic's recent poor run is that they haven't won in the East End of Glasgow since Hallowe'en.

“Yes, lately I agree on that," said Deila. "But we have had some very good home games as well this year, winning 5-0 [against Dundee United] and 6-0 [against Dundee] in September and October. We’ve taken a lot of points both home and away, if you look at the numbers. But if you don’t win over time then you can take the stats the other way. That’s the suffering part."

January is a crucial time of the year for Celtic, and not just because of the transfer window is open and they have more money to spend than everyone else. While the Parkhead side still have a game in hand, at home to Hamilton, to be slotted into their schedule, both they and Aberdeen have four league games to play before they meet up on a midweek night at Pittodrie on February 3. A couple of banana skins await in the form of a Scottish Cup visit to Stranraer and a Hampden League Cup semi-final showdown with Ross County.

By the time that Pittodrie meeting is done we will know far more about the success or failure of Deila's difficult second season, more able to state with some certainty whether he will still be around to front up a third bid to gatecrash the Champions League group stages. “We want to win the league as quickly as possible, so when our biggest rival is losing points it’s a bonus for us,” said Deila. "I think that date is in my diary. It’s going to be a big day but, again, there are many games before that."