Weston, despite not playing for a month with a back injury, is the fittest right back. Mark Delaney's long term injury rules him out for the season and Matt Jones and City's Steve Jenkins have failed fitness tests this week. Jenkins picked up a calf strain in Cardiff's win over Mansfield last Friday.
There is competition from Aston Villa's Rob Edwards but Weston will hopefully get the place.
Rhys started the game against Bosnia in Cardiff in February but was stunned early on when Bosnia took the lead from an attack through his side of the pitch.
''Bosnia was a great learning experience for me,'' said 22-year-old Weston, ''but I felt mixed emotions.
''I felt more comfortable as the game went on, but I was at fault for their first goal which was frustrating and I'm under no illusions about how it went.
''I didn't set the world on fire and it could have gone better.
''Having said that, I'm a young lad and I didn't think it was the worst game I've ever had.''
The injuries to Delaney and Gabbidon mean Mark Hughes cannot play his strongest defence.
''There will be changes but every one has been involved with the squad long enough to know what their job is and is capable of stepping in,'' Weston added.
''We work on these things in training and its instilled into us.
''Every one here is capable of doing a job for their country if given the chance.''
Daniel Gabbidon went to La Manga with Cardiff City this week as he bids to return to the City first team.
The other City first teamers on duty this weekend are Robert Earnshaw and Neil Alexander. Earnie is expected to be on the bench as Craig Bellamy will get the start despite his topsy turvy week which include alleged charges after a night club incident. Earnshaw is ready and waiting, he will not let Wales down and is sure to play some part in tomorrows game as he looks for back to back goals after scoring against Bosnia.
Neil Alexander will be on the bench for Scotland this week. He is with the Scottish squad as they face Iceland and Lithuania.
City have two players in the Wales U21's squad for tonights game against Azerbaijan at Jenner Park, Barry. James Collins will feature but Lee Fowler misses the game with the injury he picked up in the FAW game against Newport earlier this week.
Congratulations to all the Bluebirds who have been called upon by their country and good luck.