It is the penultimate round of Greene King IPA Championship's regular season and while three of the semi-finalists are confirmed, there is still plenty of jostling left to be done.

And perhaps the pick of the ties this weekend is at Castle Park, as fourth-placed Bedford Blues will go in hunt of sealing a top four berth should they topple Doncaster Knights.

The stakes are high for both sides, as a bonus-point win would secure second spot for the Knights, while the Blues could reel in third-place Yorkshire Carnegie with victory.

The Blues come into the game on the back of a high-scoring win against Cornish Pirates, but face a tough challenge at a side 11 points above them in the league table.

Doncaster have lost just one of their last 14 Championship fixtures, including two 17-17 draws, and in Latu Makaafi have the second highest try-scorer in the division.

London Welsh return to league action following their British and Irish Cup triumph last weekend with a mid-table clash against Cornish Pirates.

The two sides have already met four times this season with the Exiles losing twice in the pool stages of the Cup and once in the Championship, but winning the crucial cup semi-final.

Pirates lost a 100-point thriller against Blues in the last round of league fixtures and Welsh lost to Yorkshire Carnegie but then got revenge on the Leeds side with a 33-10 victory at Headingley, last weekend, to clinch the silverware.

Carnegie themselves will be looking to bounce back from their cup-final disappointment with a home game against Nottingham, live on Sky Sports HD.

They are already guaranteed a spot in the semi-finals but will want to keep up the pressure on the Knights to build up some form before the post-season showdown.

Nottingham sit comfortably in mid-table, in large part thanks to Paul Grant, whose 19 tries this season make him the division's leading scorer, but have lost four of their last six games.

Meanwhile, Bristol Rugby have an unassailable lead in the table and will aim to keep that momentum up heading into the play-offs against bottom-of-the-table Moseley.

Andy Robinson's men play host at Ashton Gate, and could stretch their winning run to 12 games with victory.

Moseley have not won in four games since a 16-11 victory over Rotherham Titans in February, but put up a strong fight in December's home game against Bristol, scoring 28 second-half points before eventually losing 39-28.

Jersey will be aiming to keep their semi-final hopes alive when they travel to second-from-bottom Ealing Trailfinders on Saturday.

The Islanders sit eight points behind the fourth-placed Blues and need to win both of their final games, one with a bonus point, while hoping Bedford fail to record a point.

The Trailfinders narrowly lost at Nottingham in the last round of fixtures, but have not won since beating Moseley in February and were toppled 35-7 when they met Jersey earlier in the season.

The weekend's other game sees Rotherham Titans take on London Scottish at Clifton Lane, and a win for the home side would see them jump above Scottish and into ninth in the table.

Round 21 fixtures

Friday April 15
Bristol Rugby v Moseley, kick-off 7.45pm

Saturday April 16
Doncaster Knights v Bedford Blues, kick-off 2.30pm
Ealing Trailfinders v Jersey, kick-off 3pm
Rotherham Titans v London Scottish, kick-off 3pm

Sunday April 17
Cornish Pirates v London Welsh, kick-off 3pm
Yorkshire Carnegie v Nottingham Rugby, kick-off 3pm Live on Sky Sports HD

Next Home Match

Friday 23rd August
1st XV Pre Season
Goldington Road