Davide Santon is urging Newcastle United owner Mike Ashley to spend in this month's market.
French international full-back Mathieu Debuchy has signed for £6million from Lille but defender Santon wants more arrivals.
Santon, 21, said: "It's not my job to sign players but the people in charge know what we have to do.
"Anyone who comes in must help us finish the season as best we can.
"We have to think positive and keep a strong mentality."