Mike Tomlin's wife has paid an emotional tribute to her husband after he called time on his 19-year spell as Pittsburgh Steelers head coach.

Earlier this week Tomlin, the longest-tenured head coach in major American professional sports, stepped down from his position in Pittsburgh and told players that he plans to step away from coaching.

When addressing the media on Wednesday, Steelers president Art Rooney II revealed the 53-year-old made the decision in order to spend more time with his family, something he's been forced to sacrifice over the past two decades.

While he never recorded a losing season in each of his 19 in charge, Tomlin's lack of playoff success - with their last postseason victory coming all the way back in 2016 - meant fans had been calling for his lengthy tenure to end in recent years. 

Yet in a statement on social media, Kiya Tomlin - his wife of almost 30 years - has heaped praise on her husband and claimed that his true legacy in Pittsburgh was helping players become 'great individuals'.

'As many of you are aware, my husband has stepped down from his position as Head Coach of the Pittsburgh Steelers. I want to take a moment to share something from my heart,' Kiya wrote on her Instagram story.

'I am incredibly proud of all he has accomplished, both on and off the field. Over the past few days, the messages and testimonies shared by current and former players - the men who knew him best - have been deeply moving. They've affirmed what I've always known to be true about his purpose and character.

'His mission began long before the titles and headlines, back when we first met in college, and it has never wavered. 

'From the very beginning, his purpose was clear: to help young men become great individuals. Coaching and fatherhood became the avenues through which he lived out that calling.

'To me, the men who passed through his locker rooms over more than 30 years of coaching, our own children, and the hundreds of young people across the region he personally poured into - that is his true legacy.

'They are his coaching tree, and that is the achievement we are most proud of.'

Kiya went on to thank the city of Pittsburgh for the 'warm reception our family has received over the past 19 years'.

Tomlin led the Steelers to Super Bowl glory in 2009, but their 30-6 loss to the Houston Texans in the wild card round on Monday night means the team has now lost seven straight playoff games, the longest active streak in the league.

The 'Fire Tomlin!' chants that initially popped up during a late-November loss to the Buffalo Bills were heard again Monday night as Acrisure Stadium emptied. 

Tomlin initially brushed off questions about the future on Monday night. He still had up to two more years on his contract and finished his postgame remarks by stressing he 'always feels optimistic' about their ability to put together a contender. 

But now he's gone and Tomlin's long spell in charge means the Steelers are looking for just their fourth head coach since 1969.

Tomlin said in a statement: 'After much thought and reflection, I have decided to step down as head coach of the Pittsburgh Steelers.

'This organization has been a huge part of my life for many years, and it has been an absolute honor to lead this team. I am deeply grateful to Art Rooney II and the late Ambassador Rooney for their trust and support.

'I am also thankful to the players who gave everything they had every day, and to the coaches and staff whose commitment and dedication made this journey so meaningful.

'I want to also thank Steelers Nation. Your passion, loyalty, and high expectations represent what makes this franchise truly special. Coaching in Pittsburgh is unlike anywhere else, and I will always take great pride in having been a steward of this team.

'While this chapter comes to a close, my respect and love for the Pittsburgh Steelers will never change. I am excited for what the future holds for this organization, and I will forever be grateful for my time coaching in Pittsburgh.'