Suazo of Mexico's Monterrey had announced his retirement from international football earlier this year but coach Jorge Sampaoli has persuaded him to return.
Valdivia, who plays for Palmeiras in the Brazilian second division, was suspended for 10 matches for indiscipline in October 2011 by Chile's former coach Claudio Borghi.
Sampaoli, the third Argentine in a row in charge of the Chile team, had recalled Valdivia for qualifiers earlier this year but the midfielder missed them through injury.
Chile are fourth in the South American group with 21 points and three matches remaining. Uruguay, who have a game in hand, and Venezuela are fifth and sixth, both with 16 points.
The top four in the group will go through to the finals in Brazil next year while the fifth-placed team will play off with an Asian qualifier for one more berth.
Uruguay welcome striker Luis Suarez back for their visit to Peru after he was suspended for the crucial 1-0 win away to Venezuela in June that put their campaign back on track.
Peru, seventh with 14 points, have included Real Madrid teenager Christian Benavente in their squad for the first time.
Argentina lead the South American qualifying group with 26 points followed by Colombia on 23 and Ecuador with 21.
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