Kris Boyd has called on Cyriel Dessers and Sam Lammers to prove their worth at Ibrox.

The former Rangers striker insists neither summer import has shown enough to justify the significant transfer fees paid to bring them to Glasgow.

Rangers paid fees reported to be worth a combined £6m for the duo who have just four goals between them this season.

And with a mounting injury list - particularly in the forward area - Boyd has demanded the pair step up and shine for Michael Beale.

Beale confirmed an injury setback to Kemar Roofe in his press conference on Friday with Danilo, Todd Cantwell, Kieran Dowell, Tom Lawrence and Rabbi Matondo also sidelined for upcoming fixtures.

For Boyd, both Dessers and Lammers have had adequate time to get up to speed in Scottish football and must perform on the pitch for Beale and Rangers starting against Aberdeen this weekend.

In his Scottish Sun column, Boyd commented: "Michael Beale shelled out the best part of £6million to bring the pair from Serie A in the summer.

"So far, the attacking duo haven’t come even remotely close to justifying those fees.

"Yes, it’s still relatively early doors for them, 13 games into what could be a long season — but how long can we keep saying that?

"Time’s not something you get much of when joining Rangers.

READ MORE: Rangers injury news pre-Aberdeen provided by Michael Beale

"And patience is not the greatest virtue of any Scottish football fan.

"Of course you’ll be given a period to settle in, but as we’re approaching October now has to be the time for Lammers and Dessers to show what they’re capable of."

On Roofe, Beale said: "Yeah he's away for a scan, so no news on that one at the minute. He didn't train today with the rest of the team.

"Until we get the news back from the scan we don't really know what we're dealing with. Obviously, it's disappointing for Kemar because he came back into the team and did so well until the other night. Let's hope it is nothing too serious and that he'll be available in the short term rather than the long term.

"It's frustrating because he's a big player and such a very good player. It's hard because he's not been as available as he'd have liked for three managers, not just myself. 

"It looked like he was in a really good place, he was contributing well, so let's hope he's just felt a niggle and come out. The right thing is to get a scan and he's up for that this afternoon."