Per Mertesacker will feature in a back three for the first time in his life should he make Arsenal's starting XI for the FA Cup final.
Arsene Wenger's team face Chelsea at Wembley on Saturday hoping to secure a trophy that would lift an otherwise disappointing season in which they missed out on qualifying for the Champions League.
Club captain Mertesacker, 32, made his first appearance of 2016-17 in last week's 3-1 defeat of Everton, appearing as a substitute after injury to Gabriel and Laurent Koscielny's sending-off.
Their absence from Wenger's squad for Saturday's fixture has taken Mertesacker into contention to start against the Premier League champions, particularly given illness could yet rule out fellow German Shkodran Mustafi.
Since his arrival in 2011 the defender had been a consistent figure in the back four Wenger has long preferred, u ntil a serious knee injury suffered last summer.
However, Wenger 's recent switch to the increasingly popular 3-4-3 means his team is one in transition, but at a time when Mertesacker's experience could prove vital against Chelsea's potent attack, the German will also be under pressure to adjust.
"I have never played in a back three, honestly," he said.
"When I was young I started in a back four and that was my position from then on for the last 15 years.
"Everyone starts from zero with that new system. It means small adjustments but what it comes down to is knowing what the others are doing and giving them information that they know what you're doing. Communication is the key in that system, even more.
"We feel more compact even in the middle and accepting sometimes 'Just defend, just defend'. We're getting the ball sometimes so just allow ourselves to relax a little bit more.
"With a back four we felt we have to get the ball, we have to play, we have to press, especially against Manchester City (in the semi-final, which the Gunners won 2-1); we allowed ourselves just to defend from the box, not even open up too much.
"It's still a learning curve though for us, the back three, and for those who haven't played that system this season.
"We had to change to a back four against Everton due to that red card, but what made the difference against Everton was the communication, especially against each other. That's what we need to do on Saturday."
Arsenal's shortage of defensive options potentially presents Mertesacker with not only the chance to re-establish himself in a changing team, but to reward Wenger for the loyalty he has shown the German.
During a season in which the manager has been under intense pressure - and his future remains the subject of uncertainty - his loyal streak has been the subject of criticism.
Mertesacker was awarded a new contract when he was still struggling with his fitness, and he said: "They had to exercise (the option to extend my contract) in December when I was injured.
"That was pretty much good motivation for me to think I am going to play again, this or next season. I was not particularly thinking 'Okay, I need to play this season'. It was more like giving myself more time not to rush.
"So it was then for me a better situation to relax a little bit more. The club trusted me that way. They trusted me that I could come back and make the difference at one stage of the season or next season.
"You have to consider that definitely (you are at risk of being released) when you're injured and that was long term. The manager backed me up, made me captain, knowing I was going to be sidelined for more than six months.
"That was the first life; the second life was to exercise the option. Obviously I'm grateful so I want to make sure I try to give something back."
In addition to Mustafi, Kieran Gibbs faces a late fitness test before Wenger selects his team. Alex Oxlade-Chamberlain is in contention to compete with Gibbs for a wing-back position after recovering from a hamstring strain, while Alexis Sanchez is expected to be passed fit after a strained thigh.