Leinster and Ireland have been handed a timely boost with James Lowe set to return this weekend.
The winger missed the opening two rounds of the Six Nations due to a hamstring injury, and will make his comeback from the bench in tomorrow's United Rugby Championship meeting with Ospreys at the RDS (live on RTÉ2).
Head coach Leo Cullen made six changes from the side that defeated Edinburgh last week.
Cian Healy, Ryan Baird and Jordan Larmour all start having been released from Ireland camp.
Healy comes in for Ed Byrne at loosehead, alongside James Tracy and Michael Ala'alatoa in the front row.
Baird partners Ross Molony at lock, replacing Josh Murphy, while Martin Moloney continues at flanker following his fine performance last week, alongside Scott Penny and tryscorer Max Deegan.
Luke McGrath captains the side on his return with Nick McCarthy dropping to the bench, joining Ross Byrne in the half backs.
Harry Byrne slots in at centre following Ciaran Frawley's facial injury, while Jamie Osborne moves from full-back to the 13 jersey.
Jimmy O'Brien returns from injury, in between Dave Kearney and Larmour in the back three.
Among those on the bench, Sean Cronin is in line to make his 200th appearance for the province.
Leinster: Jimmy O'Brien; Jordan Larmour, Jamie Osborne, Harry Byrne, Dave Kearney; Ross Byrne, Luke McGrath (capt); Cian Healy, James Tracy, Michael Ala'alatoa; Ross Molony, Ryan Baird; Martin Moloney, Scott Penny, Max Deegan
Replacements: Sean Cronin, Peter Dooley, Tom Clarkson, Jack Dunne, Rhys Ruddock, Nick McCarthy, Rory O'Loughlin, James Lowe
Jack Carty (above) returns from international duty to take his place on the Connacht side for their trip to Scarlets on Saturday (kick-off 7.35pm).
Carty came on two minutes from the end in Ireland's 30-24 defeat to France last weekend.
Also returning from the international camp is Dave Heffernan, who starts alongside Jordan Duggan and Tietie Tuimauga in the front row, with lock Niall Murray alongside Leva Fifita.
Elsewhere in the six changes made by coach Andy Friend, Tom Daly and Sammy Arnold resume their centre partnership while John Porch, who makes his 50th appearance for the club, moves to the wing with Peter Sullivan on the opposite wing and Tiernan O'Halloran at full-back.
The back-row consists of Paul Boyle at number 8 beside flankers Cian Prendergast and Jarrad Butler.
Kieran Marmion will become the fifth Connacht player to reach 200 caps when he lines out in Wales.
Connacht: Tiernan O’Halloran; Peter Sullivan, Sammy Arnold, Tom Daly, John Porch; Jack Carty (capt), Kieran Marmion; Jordan Duggan, Dave Heffernan, Tietie Tuimauga; Niall Murray, Leva Fifita; Cian Prendergast, Jarrad Butler, Paul Boyle
Replacements: Shane Delahunt, Greg McGrath, Jack Aungier, Eoghan Masterson, Abraham Papali’i, Caolin Blade, Conor Fitzgerald, Tom Farrell
Tullamore's Cormac Izuchukwu (above) will make his long awaited return from injury for Ulster in their trip to second from bottom Deagons on Sunday (kick-off 2pm).
The rapid second row has been sidelined since suffering a torn anterior cruciate ligament last April, and is set for his first appearance of the season off the bench.
Dan McFarland's league leaders have been further boosted by the availability of several internationals, with Robert Baloucoune, James Hume, Tom O'Toole, Nick Timoney and Kieran Treadwell all returning from national camp.
Baloucoune joins Ben Moxham and Rob Lyttle in the back three, while it's a first choice centre partnership as Hume reunites with Stuart McCloskey for their first game together since December.
With John Cooney still inured Nathan Doak continues to partner Billy Burns behind the scrum.
O'Toole returns to the starting side at tighthead prop, alongside John Andrew and Andrew Warwick who gets the nod over Eric O'Sullivan at loosehead.
Treadwell's return sees Alan O'Connor rested, as he joins Sam Carter in a powerful looking second row.
Nick Timoney comes in at number 8 with Duane Vermeulen given a weekend off, and he captains the side this weekend, packing down either side of Davis McCann and Marcus Rea.
Ulster: Rob Lyttle; Robert Baloucoune, James Hume, Stuart McCloskey, Ben Moxham; Billy Burns, Nathan Doak; Andrew Warwick, John Andrew, Tom O'Toole; Kieran Treadwell, Sam Carter; David McCann, Marcus Rea, Nick Timoney (capt)
Replacements: Brad Roberts, Eric O’Sullivan, Marty Moore, Cormac Izuchukwu, Matty Rea, David Shanahan, Ian Madigan, Stewart Moore.
Listen to the RTÉ Rugby podcast on Apple Podcasts, Soundcloud, Spotify or wherever you get your podcasts.
Watch live coverage of Leinster v Ospreys on Saturday 19 February on RTÉ2 and RTÉ Player, with coverage starting at 4.30pm.
