"We're keeping an open mind about the situation at the moment, but we're definitely on the lookout for a hooker," Scarlets director of rugby Gareth Jenkins said. "Matthew looks like being out for a month or so, so that leaves us with Aled. As well, we'll bring Craig Hawkins into the squad for Wednesday."
The Scarlets play a regional selection XV at Llandovery tomorrow night, and Jenkins confirmed former Wales Youth player Hawkins will start at hooker.
"It's a short-term problem, but obviously if Robin receives bad news from the specialist, we have to reconsider and look at a long-term solution."
Jenkins said the Scarlets emerged relatively unscathed from Saturday's 24-20 loss to Worcester, with only backs Barry Davies (arm) and Lee Byrne (knee) suffering slight knocks. Meanwhile, Blues centre Tom Shanklin (knee) is making good progress after returning home early from the British and Irish Lions tour of New Zealand.
Shanklin says he is strengthening his knee through swimming and "can't wait" to get back into action. His resolve is good news for Blues coach David Young, who goes into the Celtic League without all three of his front-line centres.
Shanklin, Jamie Robinson (knee) and new signing Marc Stcherbina (shoulder) are all out, although Tristan Davies played well against Pontypridd on Saturday and captain Rhys Williams can play in the No 13 jersey.