The midfielder revealed earlier in the week that he is now unlikely to sign a deal with Swansea and Jenkins is awaiting a confirmed decision.
"There is always that risk when you take a player on loan that he does well for you and other clubs then become interested," said Jenkins in the Wigan Evening Post.
"The fact is that he is Hoffenheim's player, not ours, and at this stage I have no idea whether he will be coming back to us on a permanent basis.
"Gylfi's agent hasn't told me anything about what's happening. For whatever reason they have decided to draw out the process and we will probably find out a lot more about what Gylfi's decisions are over the next few weeks.
"I have got no idea what the timescale is to sort things out as far as Gylfi is concerned.
"As things stand, I can only assume that he will be back at Hoffenheim come the start of pre-season training."