A native of Tepeji, Mexico, Jimenez will wear El Tri's No.9 jersey at the World Cup.
The Mexico worldwide forward is away with his country ahead of the World Cup in Russian Federation and will replace Benik Afobe who joins Championship side Stoke City for £12m just days after signing for Wolves in a £10m deal. All told, Jimenez scored 39 goals in 102 appearances for America over four seasons before heading to Europe.
Jimenez, 27, has made 120 appearances for the Portuguese side over three seasons since coming over from Atletico Madrid, scoring 31 times.
The 6ft 1in forward is in Mexico's squad for this summer's World Cup in Russian Federation and has netted 13 goals in 63 games for his country.
At the 2012 Olympics in London, Jimenez came on as a late substitute in Mexico's 2-1 win over Brazil in the gold-medal match at Wembley.