Image source, Rex Features

Harlequins fly-half Marcus Smith is "desperate to deliver trophies" for the club.

"It's a long time since this club has been in the top four," the 22-year-old said.

"We've spoken about how big an opportunity this is for this group and the club.

"Bristol have been leading the charge this season and I am very excited for the challenge."

Image source, Rex Features

After sealing top spot, Bristol Bears director of rugby Pat Lam has encouraged his players to go on and make history for the club.

"We said it was a race to the top of the mountain, and we won the race," Lam told BBC Radio Bristol.

"Now there are four teams standing at the top of the mountain, and the next two weeks are about which team gets to put the flag in the mountain.

"That is the one which is remembered and can't be removed. It is locked in history."

Danny Care
Harlequins and England scrum-half on BBC Rugby Union Weekly

We are excited. It is the first time Harlequins have been in the semi-finals for seven years. We know we are going in as massive underdogs but we don’t mind that. We are looking forward to the challenge.

We know what Bristol are all about – they are a brilliant side and very well coached. One thing for us is we are not going there to die wondering.

We will go down there and embrace the challenge. We have a lot of players leaving this year and would love to end on a high and get to that big dance at Twickenham.

Danny Care
Harlequins and England scrum-half on BBC Rugby Union Weekly

We are hopeful what we can do on the pitch can cause them some problems. We have got to play a very good game to get the result we want. We are not sure on what is happening next year, but we have two games to make some unbelievable history.

If you look at where we were four, five, six months ago, to say we’d be in a semi-final and two games away from winning the Premiership, it’s ridiculous.

Image source, Rex Features

As ever, we'd love to hear from you throughout the afternoon's action on social media.

Who's your tip for the title? Is it finally Bristol's turn to knock Exeter off their perch or are we in for a surprise package this season?

Let us know using #bbcrugby

Image source, Getty Images

Harlequins are making their first appearances in the play-offs in seven seasons.

Dino Lamb drops to the bench to allow club captain Stephan Lewies to start at lock.

The only other change from last Saturday's win against Newcastle sees Scotland international James Lang replace wing Cadan Murley among the replacements.

Harlequins: Green; Lynagh, Marchant, Tapuai, Morris; Smith, Care; Marler, Baldwin, Louw, Symons, Lewies (capt), Lawday, Kenningham, Dombrandt.

Replacements: Gray, Garcia Botta, Collier, Lamb, J Chisholm, Landajo, Lang, Northmore.

Image source, Getty Images

Bristol finished the season top of the pile and narrowly beat Quins in a tasty regular season encounter on the same ground back in March.

Among their changes from a win at Leicester on 5 June, full-back Charles Piutau returns and England prop Kyle Sinckler starts against his former club.

Winger Luke Morahan and scrum-half Andy Uren come into the back line, while Max Malins switches from full-back to the wing.

Hooker Harry Thacker comes in while a late change in the back row sees Dan Thomas miss out with a dead leg and England's Ben Earl start at openside flanker.

Jake Heenan is the late addition on the bench.

Bristol: C Piutau; Morahan, Radradra, S Piutau (co-capt), Malins; Sheedy, Uren; Y Thomas, Thacker, Sinckler, Attwood, Vui, Luatua (co-capt), Earl, Hughes.

Replacements: Capon, Woolmore, Afoa, Joyce, Heenan, Randall, Lloyd, O'Conor.

Image source, BBC Sport

Kick-off on the way in less than half an hour, so let's bring you the team news from Ashton Gate...

A first home Premiership semi-final for Bristol and there's plenty in already at Ashton Gate.

We're expecting 6,000 socially-distanced supporters this afternoon. It's great to have fans back.

Image source, BBC Sport

Image source, BBC Sport

Image source, BBC Sport

Image source, Getty Images

Twenty-two relentless rounds of Premiership rugby union done since mid-November and now we're down to the last four teams standing in the race for the trophy.

It's Premiership semi-finals time and both ties are back-to-back this afternoon with a place at Twickenham next Saturday on offer for the winners.

Welcome along! Here's what's on the way:

Ashton Gate: Bristol Bears v Harlequins (13:30 BST)

Sandy Park: Exeter Chiefs v Sale Sharks (16:30 BST)