Less than an hour after being presented to the home support at the City Ground, Ortega saw Forest's No1 Matz Sels forced off at halftime in their 1-1 draw with Crystal Palace.
Afterwards, Dyche confirmed: "He's got what we think is a groin injury. He'll have a scan as soon as possible."
Forest had the lead through Morgan Gibbs-White before Ismaila Sarr converted from the spot for Palace at halftime. Forest also had Neco Williams sent off from the incident.
"The half-time changes the whole feeling of the game.
"We had some real quality play. The mistake forces the corner. I think it's an instinctive reaction from Neco. I'm not going to question him on that.
"We changed the shape and went to 4-3-2. We have good strength at the back but we did well to contain it. So many good performances today.”