Ulster's Billy Burns and Stuart McCloskey are among 13 players to have been released by Ireland before this weekend's Pro14 return.

Ulster face Ospreys on Saturday during a break in the Six Nations tournament.

Jack McGrath and Tom O'Toole have also been released as Ireland embark on a two-day training camp in Cork.

Ulster scrum-half John Cooney has been retained by Ireland coach Andy Farrell after featuring in the wins over Scotland and Wales.

Connacht pair Ultan Dillane and David Heffernan, Leinster quintet Max Deegan, Dave Kearney, Ronan Kelleher, Luke McGrath and Will Connors, and Munster duo Chris Farrell and Jack O'Donoghue round out the 13 players released back to their provinces.

Conference A leaders Leinster host Cheetahs on Saturday with Munster also at home to South African opposition as Southern Kings visit Thomond Park, while Connacht are at home to Cardiff Blues in Conference B.

Ireland will continue their bid for the Grand Slam when they take on England at Twickenham on 23 February.

Ireland squad for Cork training camp:

Backs:

Will Addison (Ulster), Bundee Aki (Connacht), Ross Byrne (Leinster), Andrew Conway (Munster), John Cooney (Ulster), Keith Earls (Munster), Robbie Henshaw (Leinster), Jordan Larmour (Leinster), Conor Murray (Munster), Jonathan Sexton (Leinster), Jacob Stockdale (Ulster).

Forwards:

Caelan Doris (Leinster), Tadhg Furlong (Leinster), Cian Healy (Leinster), Iain Henderson (Ulster), Rob Herring (Ulster), Dave Kilcoyne (Munster), Peter O'Mahony (Munster), Andrew Porter (Leinster), James Ryan (Leinster), CJ Stander (Munster), Devin Toner (Leinster), Josh van der Flier (Leinster).