Duncan Watmore and Paddy McNair have stepped up their recovery from injury ahead of pre-season.
The pair suffered ACL injuries within weeks of one another, McNair in the 3-0 win over Hull in late November and Watmore in the 2-1 win over Leicester in early December.
They did not feature again as the Black Cats were relegated but both were a major part of David Moyes' plans for next season, as they are certain to be under whoever inherits the Stadium of Light dugout.
Both players are currently stepping up their recovery in Portugal. The rest of the squad are due to report to the Academy of Light for the start of pre-season training in ten days time, with a camp in Austria to follow soon after.
McNair is likely to be slightly ahead of Watmore in his recovery, with the 23-year-old forward suffering a setback in April.
David Moyes said at the time it could add a month to his recovery.
McNair is hoping to be a key part of Sunderland's midfield next season and told the Echo in March that he intends to help try and solve the Black Cats lack of goals going forward.
"“I think I’ll play midfield going forward, Sunderland signed me as a midfielder, I play there for Northern Ireland as well," he said.
“I know I played a lot at centre-back under Louis van Gaal, that was his opinion of my best position, but the majority of coaches and managers think I’m better in midfield,
“I don’t really just want to be just a sitting player, sitting in the centre circle. I want to get about, when I was younger my hero was Steven Gerrard, a brilliant player."
The 22-year-old also said Watmore had been a crucial part of getting over the injury: "Duncan has done the same injury as me so that’s really helped, doing everything the same, I’m helping him, him helping me.
“I couldn’t really imagine doing it on my own, it sounds bad, but I think Duncan’s happy I’m doing it with him and I’m definitely happy to have him. “I got my operation a week ahead of Duncan, so I was winding him up, telling him I was a week ahead, you know.
“There’s a good bit of craic, some days you know I came in and it’s like, you’re devastated, you know. Some days he’s like that too so we can push each other along.”