Leadbitter tweaked a hamstring as he scored the penalty which gave his side a 2-1 lead in last Saturday’s 3-3 draw with his former club Sunderland, and Pulis has revealed he has ‘an outside chance’ of being fit.
Winger Adama Traore will definitely be available following a successful appeal against the red card – his second of the season – he received at the Stadium of Light which would have resulted in a four-game ban.
However, striker Rudy Gestede is out for the rest of the season after undergoing surgery an a fractured ankle, while full-back Fabio da Silva is still out with a thigh problem.
Leeds manager Paul Heckingbottom could have a trio of players available once again for the trip to the Riverside Stadium.
Boro old-boy Adam Forshaw missed last Saturday’s 1-0 home win over Brentford after his wife went into labour and is expected to return.
Midfielder Pablo Hernandez also missed out as he continued his recovery from a groin injury, and he too could make the squad.
Striker Kemar Roofe will hope to resume after sitting out against the Bees because of a knock.
West Ham are reportedly set to pull out of their plan to sign central defender Alfie Mawson from Swansea this summer.
Brighton have been linked with a swoop on League One Sunderland for the signature of goalkeeper Jason Steele.