Saracens number eight Ernst Joubert makes his final appearance before retiring today.

And the South African has picked quite a stage on which to hang up his boots, with his last outing coming at Twickenham.

The 35-year old joined Sarries in July 2009 and has won two Premiership titles with the club, as well as the LV=Cup last season.

With Saracens on a nine-match winning run in all competitions, can Joubert help the north Londoners to one last victory against Worcester?

Image source, BBC Sport

Second versus third has just got under way at Sandy Park.

It's suddenly all go at the AJ Bell Stadium, as first Mike Delany and Danny Cipriani trade penalties and then Rob Vickers crosses to edge Newcastle ahead.

Tom Catterick misses from the tee, but Dean Richards will be pretty chuffed with that response from his side.

Adam Williams
BBC Sport at Twickenham

Image source, BBC Sport

It's two games for the price of one at HQ this afternoon.

Not the traditional London Double Header we've seen in recent years, but no less mouth-watering.

First up, defending champions Saracens face promoted Worcester, before conquerors of European giants in recent weeks Wasps face winless London Irish.  

England full-back Mike Brown makes his 250th appearance for Harlequins, who make eight changes to the side which won at Cardiff Blues in the European Challenge Cup.

Captain Danny Care and Nick Evans return in the half-backs as George Lowe is named at outside centre.

James Horwill and Chris Robshaw come into the forward pack, while Dave Ward is named in the back row.

Image source, BBC Sport

Replacements: Gray, Lambert, Collier, Matthews, Treadwell, Tebaldi, Swiel, Hopper.

The BBC Newcastle commentators - who you can listen to via the 'Live Coverage' tab - are suggesting that this has, so far, been Falcons' best performance this season.

Still they work through the phases patiently, but still they trail to Danny Cipriani's early penalty.

Second-placed Exeter Chiefs make several changes to the side which beat Bordeaux in the European Champions Cup as they welcome third-placed Harlequins to Sandy Park.

Forwards Mitch Lees, Dave Ewers, Don Armand and Thomas Waldrom are recalled, while fly-half Gareth Steenson returns.

Henry Slade switches to centre, with James Short named on the wing.

The Chiefs have also made a late change to their starting line-up, with Alec Hepburn now named in the XV at loose-head prop and Ben Moon dropping to the bench.

Image source, BBC Sport

Replacements: Taione, Moon, Brown, Parling, Johnson, Lewis, Hill, Woodburn.

Worcester make their first-ever Premiership appearance at Twickenham this afternoon.

The Warriors have never played a game of 15-man rugby at the national stadium before, but they have appeared in the Middlesex Sevens on seven occasions.

Dean Ryan's side are yet to win away from home in the league this season and have lost their last three meetings with Sarries.

Can the Warriors record a landmark victory on their Twickenham debut?

Now seems like as good a time as any to point you in the direction of our BBC local radio coverage of this afternoon's action.

You can follow every cough and spit of every match by popping up to the 'Live Coverage' tab at the top of this page and selecting your commentary of choice.

There's not been a huge amount to shout about in the match between Sale and Newcastle with 10 minutes gone. Newcastle have had a decent chunk of the ball and, as I type, are on the attack.

Image source, Getty Images

Having finished outside the Premiership's top four last season for the first time since 2010-11, Harlequins have rediscovered their form this term with three wins from four.

Conor O'Shea's side come into the trip to Devon in third place on the back of two impressive wins in Europe's Challenge Cup.

Between Danny Care, Nick Evans, Ben Botica and Karl Dickson, Quins have four good halves to guide them around the pitch.

Image source, Getty Images

Exeter Chiefs are currently in the heady heights of second place in the Premiership, following their impressive win against Leicester before the European break.

Thomas Waldrom is one of seven changes to the Chiefs side, and could again be key against Harlequins this afternoon.

Last season's Premiership top-scorer ran in one of his 16 league tries in the Chiefs' 36-13 thrashing of Quins at Sandy Park last season.

Danny Cipriani kicks the first Premiership points of the afternoon to put Sale Sharks ahead against Newcastle Falcons.

Craig Maxwell-Keys is the man in the middle at the AJ Bell this afternoon - and his whistle prompts Danny Cipriani to boot the ball long and get us under way.

Winger Marcus Watson starts his first Premiership game for Newcastle Falcons after scoring four tries against Enisei-STM in the European Challenge Cup.

Centre pairing Adam Powell and Juan Pablo Socino return while Nili Latu comes into the side at number eight in place of Dan Temm.

The Falcons sit bottom of the table and are yet to pick up a point in the league this season.

Image source, BBC Sport

Replacements: Lawson, Rogers, Vea, Botha, Hogg, Tipuna, Catterick, Harris.  

Sale Sharks have been forced into a late change for the visit of Newcastle to the AJ Bell Stadium after Josh Beaumont failed a fitness test.

TJ Ioane comes into the side at number eight in his stead while Viliami Fihaki is named among the replacements.

Captain Dan Braid and fly-half Danny Cipriani return to the starting XV after being rested for the European Challenge Cup victory over Pau.

Prop Eifion Lewis-Roberts could make his first outing this term from the bench after an ankle injury.

Image source, BBC Sport

Replacements: Neild, Lewis-Roberts, Mujati, Ostrikov, Fihaki, Stringer, Ford, Jennings.  

Image source, Getty Images

Newcastle could really do with a victory, couldn't they?

The Falcons have lost all four of their opening fixtures and have yet to register a single point. I mean, even London Welsh had picked up a point by this stage last season - though it was the only point they managed all campaign.

Sale, meanwhile, have been typically inconsistent - an eye-catching victory over Northampton at the start of the month only coming after a hammering by Saracens in round one.

So which way will it go today?

Image source, Rex Features

And, before it all kicks off at Twickers, Harlequins travel to fellow play-off hopefuls Exeter Chiefs at 15:00 GMT and Sale Sharks host Newcastle Falcons at 14:30 GMT.

Speaking of which...