Director of football Graeme Bennett confirmed Kaiserslautern had expressed their interest in Niculae.
"We have had an inquiry from Kaiserslautern. They have not made a bid although they said they were going to," Bennett told the Press & Journal.
"I met with Marius last week and I said I would keep him abreast of any interest in him. I told him we received two offers and I did not think they were acceptable and he was quite happy with that.
"He played in Germany before and teams know him.
"He has played in the SPL for a season and I don't think it would be a big gamble for a team in Germany to take him, although we are not under any pressure to sell him.
"We have made a huge financial commitment with Marius and we want to make our money back.
"If no-one comes up with a realistic offer we will keep him for a second year and he is factored into our budget for this season.
"The transfer window runs until August 31 and we may have to wait until then."