Sigurdsson sat out the Swans' 2-0 pre-season victory at Birmingham on Saturday, with the club saying it was due to the "current transfer speculation surrounding him".
It is thought Premier League rivals Everton have lodged a bid of around £40million for the Icelandic playmaker, with potential add-ons that could take a final package closer to £45m.
But Swansea value Sigurdsson at £50m and are holding out for that fee, with American owners Steve Kaplan and Jason Levien having said they will not be "bullied" into selling their prize asset.
"It was decided between me and the club, and him also, that it was the best decision for everybody involved that he wouldn't take part in games at this point," Clement said after the Birmingham win.