The 27-year-old, who plays for Championship club Derby, was in goal for Sweden in their final World Cup qualifier against Slovenia in November. But he was unavailable to play when the Blues secured their World Cup place in the playoff matches against Ukraine and Poland recently.
Now, however, he appears to be on his way back from the viral illness that has kept him away since the end of January, Aftonbladet reports, citing local British media.
"He's more involved in training. There are still a few things he can't do, but it's been moving in the right direction in the last week," coach John Eustace told Derbyshire Live.
