It's no secret that Celtic are having a fantastic season under summer appointment Brendan Rodgers.

There have been many factors in making that happen; new signings, the emergence of Mousa Dembele, the manager's tactics, a steely determination to win. However, there's another reason Celtic have been so dominant this year compared to seasons past.

Rodgers has transformed the form, the playing style and the careers of a number of Celtic stars who were already at the club. Turning them from inconsistent players whose futures were in the balance to some of the best players in the team, the former Liverpool manager has worked miracles will some this season.

It's meant that the Hoops haven't really had to invest heavily to maintain their dominant position in Scottish football or make inroads into European football.

These are the FOUR players whose Celtic careers has been turned around by the arrival of Rodgers...

Scott Brown

There were serious question marks over Scott Brown's future career at Celtic after Ronny Deila's second season. Unconvincing in the league for large spells and being beaten in the cups, notably by Rangers, some supporters wondered whether they had seen the best of their captain.

Fortunately for those fans, that wasn't the case. Brown is arguably having his best season ever in a Celtic shirt, a major contender for Player of the Year awards at the end of the season.

Rodgers has given him a new defensive-minded role in the time. Restraining his running and swashbuckling nature, Rodgers has ensured the Scotland international is now more disciplined and focused in the heart of the Celtic midfield.

No longer able to do the running he once could, the new, more composed Brown has been the beating heart of everything good that has happened at the club this season.

He's never looked more vital and capturing this form has been a massive part of Rodgers' unbeaten domestic run as Celtic manager.

James Forrest

James Forrest looked set to leave the club last season, failing to sign a new contract and apparently willing to let his deal, which was due to run out in December, expire. Rodgers' arrival changed everything and the new boss convinced the winger to stay at the club and fight for his place in the side.

Refreshed and revitalised, he's been one of the Bhoys' best players this season, combining wonderfully with his team mates to be the key attacking threat on the right flank.

With six goals and over ten assists, the winger is at the top of his game and is showing no signs of slowing that form down as we head into the closing months of the season.

The fact he is still considered first choice over Patrick Roberts by Rodgers shows his importance to the team and to the manager. Forrest has always had talent but his new boss has managed to add consistency to his game and it's taking his contributions to the next level.

Stuart Armstrong

Stuart Armstrong is is perhaps the player who has undergone the most dramatic transformation this season and it appears to be all down to the manager.

Basically a bit-part player when Rodgers arrived, Stuart Armstrong had failed to become a consistent and key performer under Ronny Deila, usually utilised in an attacking midfield role on the left or right flanks. However, that's not where Armstrong wanted to play and he seized his chance of a change in role when the new manager arrived.

Best explained by Rodgers himself, what happened last summer was a huge factor in his emergence as a wonderful central midfielder.

Quoted by ESPN, Rodgers said:

"We spoke to him a lot in preseason in terms of his position and where he felt most comfortable, and at that time it was maybe difficult for him to get a game in his preferred position. But what he has done, each day from that, he has looked to improve and understand the tactical element of playing on the inside."

That determination to succeed is admirable but was only possible with the backing and foresight from Rodgers to understand that he could be effective alongside the likes of Scott Brown rather than shunted out on the left.

Now he's being tipped as a future Celtic captain, a regular Scotland international and a high-value asset for the club in the transfer market.

Dedryck Boyata

Brendan Rodgers' most recent project at the club has been Dedryck Boyata. Once forgotten, he's emerged into a first choice centre-back, or at least one who can compete regularly with Erik Sviatchenko and Jozo Simunovic as a starter in the manager's XI.

Boyata didn't make a single appearance in the season until November and then was left out of the side again until January. However, that second chance has been taken by the Belgian international, going on to play in the next six fixtures.

Looking infinitely more composed on the ball than last season, he's been a commanding presence both in defence and in attack, notching up two goals from set pieces.

If he can maintain this form like Armstrong, Forrest and Brown then he'll be just the latest feather in Rodgers' cap, providing more evidence that the Celtic boss is one of the best man managers around.