Rangers manager Ally McCoist says discussions have taken place with Kyle Lafferty over a new contract.
Nothing has yet been agreed and Jordan McMillan has also mulling been offered new contract.
"There is still big room for improvement and we would look for more consistency," said McCoist.
"Kyle has done absolutely fine but we are aware that he can do more and Kyle is aware that he can do more and hopefully he can do more here."
The 24-year-old forward is out of contract at the end of next season having joined Rangers from Burnley in 2008 for £3.25m.
Lafferty, who has 31 caps for Northern Ireland, has scored 35 goals for Rangers.
"There has definitely been progress, I don't think there is any doubt about that," McCoist said. "It's our job to continue that progress.
"I think Kyle himself would tell you he's far away from the finished article.
"The coaches and Kyle himself need to keep working in that direction for him to continue the improvement."
Rangers manager Ally McCoist on trialist Joe Sise
“We would like to see him in a game and hopefully he can play in a game at the start of next week”
Defender McMillan, 22, came through Rangers' youth ranks and has had loan spells at Hamilton, Queen of the South and Wrexham.
His only appearance so far this season was in a 3-0 win at Motherwell in August and his current contract expires next summer.
"As yet, Jordan's representatives haven't got back so I haven't heard but I would imagine we would hear in the very near future," said McCoist.
Meanwhile, McCoist hopes to assess
trialist Joe Sise
further next week.
"He's looked fine," added McCoist. "He has been training for a couple of days and hopefully we'll get a practice game at the beginning of next week.
"With a bit of luck Joe will be able to play in that. I've had a look at him over the last couple of days and he looks fine and he knows where the goal is.
"But we would like to see him in a game and hopefully he can play in a game at the start of next week."