The 31-year-old has failed to secure first-team football at Ibrox and could decide to leave the club.
“There is maybe only so long before I feel I need to get back playing,” Alexander told the Daily Record.
“If it’s not here, maybe it will have to be somewhere else. I’ve got another year on my contract and I have plenty of time.
“Allan is doing well, so we’ll have to wait and see. Myself and Allan get on well and work well together but, at the end of the day, it’s my career.
“As much as I love it here and I would love to stay for a long time, I feel I need to be playing. I’ve got something in mind and we’ll see what happens.
“You never know, there might be clubs looking at my situation and taking note of it but I can only do well for myself.
“If I’m here and Allan leaves, or I leave and Allan’s here, that is just a situation that will be weighed up. But if Allan stays, it is something I will have to think about.”
