Munster coach Rob Penney has made eight changes to the side that beat Glasgow last week for Saturday night's top of the table Pro 12 clash meeting against Ospreys at Thomond Park (7.15pm).
Munster have been boosted by the return of Donncha O'Callaghan and James Coughlan from international camp, with O'Callaghan named in the secondrow and Coughlan among the replacements.
Penney has named a new frontrow in Dave Kilcoyne, Damien Varley and BJ Botha, while Dave Foley will partner Donncha O'Callaghan in the secondrow.
Dave O’Callaghan takes over from Peter O’Mahony at blindside with Varley talking on the captaincy.
Felix Jones returns at fullback after a slight ankle sprain ruled him out of action last weekend, with Johne Murphy moving to the right wing in place of Andrew Conway, who is out with bruised ribs.
There is also a new partnership at halfback, where Ian Keatley and Duncan Williams take over for JJ Hanrahan and Conor Murray.
Ulster coach Mark Anscombe has also made eight personnel changes and three positional switches to the team that recorded a bonus point win over Cardiff last Friday night for Saturday's game against the Scarlets at Parc Y Scarlets (kick-off 6.30pm.
Anscombe is boosted by the release of Andrew Trimble and Roger Wilson from the international camp at Carton House and they are named on the right wing and openside flanker respectively.
Jared Payne is named at fullback after Stuart Olding was ruled out with a concussion and he also takes over the captaincy from Johann Muller, who has been ruled out for a month with a calf injury.
Michael Allen takes over from Tommy Bowe on the left wing, while Darren Cave and Chris Farrell make up a new midfield pairing. Ruan Pienaar shifts to outhalf, with Paul Marshall starting at scrumhalf.
In the frontrow, Rob Herring takes over from Rory Best at hooker, while there is a new secondrow in Lewis Stevenson and and Neil McComb.
In the backrow, Wilson shifts to blindside to allow for the return of Nick Williams at number eight.
Connacht have made four changes from the side that lost to Leinster at the RDS last weekend for Saturday's visit of Glasgow to the Sportsground (5.0pm).
There’s a welcome return for Dave McSharry for his first start in 10 months and he is named at inside centre. The 23-year-old marked his return from injury last month by coming on as a replacement in the 33-6 Heineken Cup victory over Zebre.
Joining McSharry in the centre is 20-year-old Darragh Leader who made his first senior appearance away to Ospreys last season.
Connacht's leading try scorer Fionn Carr is named on the right wing in a back three featuring Gavin Duffy and Matt Healy.
Up front, Jason Harris-Wright will start as hooker in his 25th appearance for the province.
The replacements bench includes veteran tighthead Nathan White who returns after a three-week absence due to injury. Mick Kearney is also included in the matchday squad and could earn his first appearance of the season.
MUNSTER (v Ospreys, Saturday, Thomond Park, 7.15pm) : F Jones; J Murphy, C Laulala, I Dineen, R O'Mahony; I Keatley, D Williams; D Kilcoyne, D Varley (capt), BJ Botha; Donncha O'Callaghan, Dave Foley; Dave O'Callaghan, S Dougall, CJ Stander. Replacements: D Casey, J Cronin, J Ryan, B Holland, J Coughlan, C Sheridan, JJ Hanrahan, C Bohane.
OSPREYS: R Fussell; A Natoga, J Spratt (capt), A Bishop, B John; M Morgan, T Tibaldi; M Thomas, S Baldwin, J Rees; L Peers, J King; J Bearman, S Lewis, M Allen. Replacements: M Dwyer, N Smith, D Suter, R Hughes, A Ellis, T Habberfield, S Davies, H Dirksen.
SCARLETS (v Ulster, Saturday, Parc y Scarlets, 6.30pm): G Owen; N Reynolds, G Maule, A Warren, J Williams; S Shingler, G Davies; P John (capt), K Myhill, S Lee; J Ball, G Earle; A Shingler, J Turnbull, S Timani. Replacements: D Harris, R Evans, J Adriaanse, J Synman, J Barclay, A Davies, A Thomas, C Knight.
ULSTER: J Payne (capt); A Trimble, D Cave, C Farrell, M Allen; R Pienaar, P Marshall; C Black, R Herring, J Afoa; L Stevenson, N McComb; R Diack, R Wilson, N Williams. Replacements: N Annett, K McCall, R Lutton, M McComish, S Doyle, J McKinney, R Andrew, D McIlwaine.
CONNACHT (v Glasgow, Sportsground, Saturday, 5.0pm): G Duffy; F Carr, D Leader, D McSharry, M Healy; D Parks, K Marmion; B Wilkinson, J Harris-Wright, R Ah You; M Swift (capt), C Clarke; M Fifita, J Heenan, G Naoupu. Replacements: D Heffernan, JP Cooney, N White, A Muldowney, M Kearney, P O'Donohoe, C Ronaldson, T O'Halloran.
