The France international striker had been due to face Sunderland on Saturday but his manager withdrew him after a breakthrough was made on a deal to take him to Stamford Bridge.
The Blues reignited their interest in the France international after reaching a deal to loan Fernando Torres to AC Milan.
Remy was not included in the Rs' squad to face Sunderland in the Premier League on Saturday, which the former Tottenham boss confirmed was due to a transfer development.
Asked by Sky Sports News about Remy's situation, Redknapp explained: "I just got a phone call at about 12 o'clock today - he was going to play - to say it looks like he's going to be moving.
MORE: Alex Morgan upset at 159-degree temps | Transfer photos
"I spoke to the boy. It's difficult - the deal looks like it's probably done. I had to make a change in the team. He didn't refuse to play, I just felt it's difficult if he's getting a move tonight and signing for another team to go out there with his head around playing today. I felt it's better if we go with someone who's going to be here and part of what we're doing, and got nothing else going on in his head."
When asked if Chelsea was the team close to a deal, he replied: "As far as I know, yeah."
Remy nearly joined Liverpool earlier this summer, having spent last season on loan with Newcastle, but the move broke down after reports of a failed medical.