Sky Sports understands a number of teams from the Championship and League One were taking a close look at the Malian striker.
The 33-year-old spent time with Sheffield Wednesday earlier this season, but he has now agreed to link up with League One promotion chasers Tranmere.
"It looks like Mamady Sidibe is going to Tranmere on loan," confirmed Tony Pulis.
Tranmere boss Ronnie Moore is hoping to make a couple of loan signings in the coming days, and he wants Middlesbrough's Ben Gibson to join Sidibe.
The young Boro stopper impressed during a spell at Prenton Park earlier in the year before injury cut short his stay.
Now fit again and the 19-year-old looks like he could be move back to the Wirrall.
Manager Ronnie Moore said: "We're hoping we can get Ben back in. We are just waiting to hear from Middlesbrough. If he comes in it gives us a different option at the back."