Angel Di Maria scored as Lionel Messi returned to the international stage for the first time in six months, helping Argentina to a 1-0 victory over Ecuador in a Copa America warmup match.

Zlatan Ibrahimovic trains in Carnago, near Milan, Italy, Saturday, Jan. 3, 2020. The 38-year-old striker signed a deal with AC Milan until the end of the season with an option to extend for another year. (Spada/LaPresse via AP)

9’s are back in vogue in Serie A. The last round of matches was a case in point, with a hat trick from Ronaldo and multiple goals from Lukaku, Immobile and Belotti. Meanwhile, Zlatan Ibrahimovic is only one game into his Serie A return with AC Milan. 9’s, his vertical moves have been in perfect synch with crossing specialists Sergej Milinković-Savić and Luis Alberto. Dubbed “LuLa,” the duo has scored 23 goals in Serie A this season — seven more than all of AC Milan.

Juventus' head coach Maurizio Sarri, right, gives instructions from the side line during the Italian Serie A soccer match between Lazio and Juventus at Rome's Olympic stadium, in Rome, Italy, Saturday, Dec. 7, 2019. (AP Photo/Gregorio Borgia)

The Serie A title race could come down to which team has the best strike force. PLAYER OF THE SEASON SO FARMartínez has burst onto the scene this season after a quiet debut campaign for Inter. Martínez and Lukaku’s partnership has been key to Inter reaching the top of the Serie A standings. It’s among the team's best starts since Luigi Riva led the club to its only Italian league title in 1970. Lazio has won the Serie A title twice in its history, the last time in 2000.