Faf du Plessis has admitted that the fourth Test of the series against England at the Wanderers could be his last on home soil.

South Africa's recent returns, du Plessis age and form, and the upcoming schedule present three compelling reasons for du Plessis to sign off next week.

His team have lost seven of their last eight Tests, du Plessis is 35, has not scored a century in more than a year and averages 21.25 in 12 innings since October 2019.

South Africa play only two Tests in the winter, against West Indies, before the T20 World Cup, which du Plessis has indicated will be a swansong. Asked if the fourth Test could be his final one at home, in the aftermath of a defeat which has made a series win impossible, du Plessis said: "Yes, most definitely, it is a possibility."

But du Plessis stressed that he remains committed to seeing out this series and guiding South Africa through their transition.

"What I didn't want to do is make a decision on emotion or where we are as a team," he said. "It's just about trying to be the strongest leader that I can be for the team. For now, that's committing to this series. The worst thing a leader can do is pull the plug mid-series and say, 'Sorry boys, I am out. I've had enough.' I don't think that's what's leadership is about. You have to stick through the tough times as well. After the T20 World Cup, I will reassess where I am.

"There isn't a lot of Test cricket left this year. There's one massive Test where we need everyone to be as strong as possible to try and draw the series. After that, there is quite a big gap and there is an opportunity then to release some of the captaincy when it comes to giving guys opportunities especially in one-day cricket."

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Du Plessis is expected to relinquish the one-day captaincy as early as Tuesday, when South Africa name their squad to play England in three matches, starting on February 4. What is less clear is whether du Plessis wants to continue playing fifty-over cricket at all, after he noted that his white-ball numbers are better than his red-ball statistics.

"If I am brutally honest with myself, at the moment white-ball cricket is where I am most successful. In one-day cricket, my stats are up there with the best in the world. In T20 cricket, my stats are up there, but at the moment in Test cricket, my stats are not where they need to be."

Du Plessis averages 47.47 in ODIs, compared with 40.23 in Tests. Du Plessis' ODI average is the third-highest of any South African, eclipsed only by AB de Villiers and Hashim Amla. He is also South Africa's third-highest all-time T20 run-scorer. He considers his Test average as "not meeting the standards at the moment," even though he recognised that his strength in the format lies in his ability to perform well under pressure.

Now, South African cricket is in the midst of its most serious crisis, post-readmission. The administrative upheaval in the last few months, coupled with the team's decline, means that South Africa are in possibly the worst shape since 1991. And that's exactly why du Plessis wants to stay on, for now.

"If you leave the team when they need you most, that's not my style," he said. "One thing that I've always shown is that I have been under pressure a lot of times as a player and I've come through those times. In tough circumstances, I've played my best innings. I think that speaks for itself.

"I can't leave the team when they need me most, as one of the leaders in the team. We are in a transition, but I can't do it forever and it has been chipping away. For now, it's what we need. I think it will make it worse if I say I'm out."

Du Plessis acknowledged that recent controversies - including the social media storm that has erupted over the dropping of Temba Bavuma - have taken their toll on him. "I try to block it out. As one should do. But, obviously, myself and everyone else are not robots. So it does get to you," du Plessis said. "It's about trying to be as mentally strong as I can and try to block out all the noise."

He also sees the value in this experience, both for himself and others around him. "It's a character builder, you try and make sure you learn about yourself even in the toughest of times so you can be strong for someone else. You might go through it yourself but someone else might see something through you that they can learn from in the future. It's a tough time but there is no running away from it. There's no escape. I am the leader of the team. It comes with the job description."

With that, du Plessis reminded everyone of the task that lies ahead of him in the next week. South Africa must win at the Wanderers to ensure they don't lose a third series in succession and fall further into the mire. On what has always been a pitch with assistance for bowlers, that means South Africa have to bat well and for that to happen, they need their senior-most players to stand up. Du Plessis knows that includes him, in a big way.

"For me now it's to be as mentally strong as possible because we need our leaders, our senior players in the team," he said. "We need to be strong. It's a tough time for all of us and we need to make sure we fight. Personally, from a runs point of view, I am not up to the level that I should be but I still have a huge role to play as a captain to make sure I lift these guys up to win a Test match in the next game."

Firdose Moonda is ESPNcricinfo's South Africa correspondent