Nils Petersen has completed a permanent transfer to Werder Bremen on a four-year contract for an undisclosed fee.
Ozkan Yildirim has signed a new contract to keep him at Werder Bremen until 2016.
Andy Little fears his Rangers career could be over at the end of the season as a result of the club's financial problems.
The striker has seen much of his time at Ibrox blighted by injury but, now fully fit, has impressed in the period since the Glasgow giants were plunged into administration.
He has featured in six of the seven games since Duff and Phelps took control of the club's affairs on February 14 and scored on three of those appearances.
The Northern Irishman is out of contract in the summer and hopes he can impress enough to extend his stay in Govan but is well aware his efforts could be in vain if Rangers are unable to offer him a new deal.
Little told RangersTV: "If the club is in a position where it is out of administration and able to offer me a contract then great, but I'm also aware that might not be the case.
"I might have to move on and there were definitely times in the past when I was injured that I thought I had maybe played my last game for Rangers.
"Having got the chance now to play it would be a real shame for me to have to leave given the circumstances of the club and not down to how I'd performed.
"I feel I've done well enough to be offered a new contract and to stay and if the club isn't able to do that, it would be a shame but that's unfortunately the position that we're in.
"It would be massive to leave because it's been probably the best spell I've ever had for the club after making my debut nearly three years ago.
"It would be a real shame if I had to leave just as I was hitting my best spell because of other circumstances, but it's something I'm aware of.
"To step in to the first team and not let myself down has been great.
"I know I can play at that level and I've really enjoyed it so I hope it's not my last games, I hope I have many more games for Rangers."
Little says the way fans have rallied behind the club during a turbulent period has only strengthened his desire to remain at Rangers.
He added: "The mutual respect that the fans and the players have had has been great and has surprised even me.
"The way they have reacted since we went in to administration has been brilliant and we're thankful to the fans that they have supported us so well.
"So clearly it's a club that I want to stay at and one that is brilliant for that reason."