Reyna required surgery but his rehabilitation is almost complete and should the American come through the home clash with Middlesbrough (7pm kick-off), he is likely to boost City’s wafer-thin squad for the visit to Norwich on February 28.
"Claudio will play for the reserves on Friday and we will assess him after that," said Keegan.
"If he doesn't suffer any kind of setback, he will be involved in some capacity against Norwich, although whether that will be in the starting line-up or on the bench remains to be seen.
“You have to remember he has only played seven times this season."
Reyna’s long-awaited return could put pressure on Joey Barton, who produced a below-par second-half performance against United on Sunday.