Onuora has been forced to act after the Imps' excellent run of seven wins in nine games has left several players on the treatment table.
Onuora is now considering new signings, with the the Whites youngsters a target after they impressed in a 2-2 draw against City's reserves earlier this month.
"Grant Brown and I were certainly impressed by what we saw from this young Leeds team" said Onuora. "With the injuries we have, the squad is just beginning to look a little threadbare".