The centre-back was stretchered off in the 0-0 home draw with Grimsby at the weekend with a knock to the knee.
However, Watts’ injury has since calmed down but he is still rated 50-50 to face the Millers. The Imps have a lot of games coming up and they do not want to risk rushing Watts back and potentially making his injury worse.
Lincoln will definitely be without Aaron Brown and Ian Pearce, who are both suspended for Tuesday’s game.
But Sutton will have on-loan Eric Lichaj back after he completed a three-match ban.