Bus was brought to Wednesday in January 2015, but he has not made too much of an impact at Hillsborough.
The Romanian striker played seven times for Wednesday last season; however he only scored once in the process.
Since Carvalhal has taken charge the 22-year-old has slipped even further down the pecking order, and his chances of playing first-team football seem very limited as things stand.
Wednesday have the likes of Gary Hooper, Fernando Forestieri, Lucas Joao and Atdhe Nuhiu in their squad, meaning that they have one of the strongest forward lines in the Championship.
As a result of this depth in their striking ranks, Bus has not played since October and he has only made three appearances all season.
The forward is said to be determined to make it to Euro 2016 with Romania, but he realises that he needs to be playing regularly to stand a chance of being included in his national team’s squad.