The 31-year-old Argentina international has missed the last 11 games after breaking two bones in his back during the 4-2 Barclays Premier League victory over Southampton on February 24.
Alan Pardew,: "Colo is training. He hasn't done full physical training - that's due to come, hopefully, this week.
"We are fingers crossed because obviously, that would be a big boost for us to have our captain back, for sure."