West Ham and Newcastle are interested in Mexico international defender Diego Reyes.
Reyes, who has 53 caps for Mexico, is a free agent after his contract at Porto expired in the summer.
Fenerbahce have made an offer for the 25-year-old centre-half.
Reyes joined Porto from Mexican side America for €7m in 2013 and made 49 appearances for the Portuguese side.
He has had two spells on loan in La Liga, with Real Sociedad in 2015/16 and Espanyol in 2016/17.
West Ham have already signed two centre-backs this summer, with Issa Diop joining from Toulouse for £21.9m and Fabian Balbuena joining from Corinthians for £6.5m.