The 23-year-old has featured just once for the Blues this season because of hamstring injury that he picked up during the summer.
However, his appearance during Monday's clash with Palace has suggested that he is close to being fit enough for a place in Robert Di Matteo's squad.
"Finally I played full 90minutes after a long time. I feel fit and enjoyed scoring a header," he wrote on Twitter.
Marin's one appearance came during a League Cup tie against Wolverhampton Wanderers.