Miguel Herrera has decided to leave Javier Hernandez out of his Mexico squad so that he can sort out his future.
Sky Sports understands that Dinamo Zagreb striker Duje Cop is attracting interest from clubs across Europe.
Newcastle boss Alan Pardew has admitted that a big signing could breathe new life into his squad but has conceded it may not happen.
The Magpies are braced for the likely departure of French midfielder Yohan Cabaye, who has been the subject of a bid from Arsenal, and are bottom of the fledgling Premier League after their 4-0 thrashing by Manchester City in the first match of the season.
Although Pardew is looking at possible replacements for Cabaye and another striker to add to Loic Remy - who has joined on a season-long loan from QPR - he is taking nothing for granted.
Pardew told the Newcastle Chronicle: "If it doesn't (happen), like anything in life, we're going to have to get on with it with what we've got.
"We've still got a very good team with Remy on top of it.
"We lost Demba (Ba) and got the other guys in in January. I still think one more would be the perfect scenario."
He added that new blood could be the perfect boost after Monday's mauling by City.
"I think a player does that to the group. A big player coming in boosts the group as well as the fans," he said.
"I'm not going to say something that I don't think is true and say 'oh, it's not affecting them'.
"I think they'd like to see another striker come in the door.
"That's something that hopefully will be done before the window shuts."
Meanwhile, former Newcastle skipper Steve Howey believes Pardew has been let down by the club's top brass. Magpies owner Mike Ashley appointed Joe Kinnear to oversee transfers but so far Remy's loan move has been the only signing.
Howey told talkSPORT: "Pardew looks fed up, he's on his own. It looks as though he's being hung out to dry.
"The owner is basically saying 'It's my team, I own the club, you get on with it' and whoever is in that situation will really struggle.
"His hands have been tied and if Alan Pardew does get the sack it would be horrendous for Newcastle.
"He doesn't really have a say in what goes on at the club at all, apart from picking the team."
Newcastle have been linked with Lyon's striker Bafetimbi Gomis and midfielder Yoann Gourcuff with Pardew watching the French club play Real Sociedad on Tuesday.