MILLWALL could be without Ben Thompson for their League One game against Southend at The Den this Saturday.
Thompson failed to emerge for the second half of the 2-0 win at Coventry City last weekend and Harris confirmed afterwards the midfielder had a tight hamstring.
Jimmy Abdou came on for Thompson at the Ricoh Arena, and Calum Butcher is also an option to start a league game for the first time since the 2-0 defeat to Bolton on October 18.
Butcher has recently recovered from an ankle problem and travelled to Coventry last weekend but wasn't in the match-day squad.
"We're not sure about Ben," Harris said. "We took him off at the weekend, we're hoping as a precaution to avoid any damage.
"We're certainly getting him looked at scan-wise to see how he goes. If there is any damage we're hoping it's only minor.
"We'll be a lot clearer on it by the middle of the week."
Image: Millwall FC