Utility back James So'oialo has been ruled out of action for three to four weeks after sustaining an ankle sprain during his full debut for the province in Parma.
The medical staff continue to monitor hooker Jason Harris-Wright who, after replacing Sean Henry during the second half against Zebre, was forced to come off 30 minutes later with a recurring bicep injury.
A scan later today will reveal if the 25-year-old will be available for the Leinster clash.
Tighthead prop Nathan White (calf) faces at least another week on the sidelines, while John Muldoon, Eoin Griffin and Eoin McKeon will be out of action until after the well-earned November break.
Looking forward to the interprovincial derby against Leinster, head coach Lam said: "It's a perfect game for us. It's a big challenge. These guys have consistently been the best team in Europe, and they are full of Irish internationals and guys who play overseas in international teams too.
"Connacht haven't beaten Leinster in Dublin since 2002, they've never won at the RDS. So it's a mighty challenge. But it's one that we are looking forward to and we talked about it this week.
"We have to just continue to build on what we are doing, take a lot of confidence out of last week and the week before, and our Europe form to now bring it back to begin the process of trying to win in Dublin."