Eric Harrison has warned Ryan Giggs if he ends up becoming the new Wales manager he would have to end his stellar career at Manchester United.[LNB] Following Friday's disappointing defeat to Montenegro, current boss John Toshack is said to have reached the conclusion that it would be better if he moved on.[LNB]Although there has been an indication Toshack would remain in his job for next month's double header with Switzerland and Bulgaria, beyond that he is believed to want no part.[LNB]In that context, it is little surprise Giggs' name as been mentioned as the Football Association of Wales' first choice.[LNB]Mark Hughes did something similar when his own playing career was coming to an end at Blackburn, with Harrison acting as a key member of his back-up team.[LNB]However, the man responsible for bringing Giggs through the Old Trafford ranks as part of that famed "Class of 92" does not believe it would be possible for the 36-year-old wide-man to combine duties at a club like United.[LNB]"It is not a cushy little number and it is not a part-time post," he told the Manchester Evening News.[LNB]"You are at the sharp end of things and these days I don't believe you could combine playing for a club at United's level and managing an international team.[LNB]"When I was with Mark we'd be jetting off all over the place watching future opponents. Then you would be going up and down the country checking on your players.[LNB]"You couldn't be playing for United at the weekend and be wondering and worrying about how the Welsh players are doing.[LNB]"If the vacancy does come up and Ryan is approached then he has a massive decision to make."[LNB]Harrison has no doubts Giggs is mentally tough enough to make a success of the management game and will become Wales boss eventually.[LNB]However, having amassed a record 11 league titles as part of a medal collection unmatched in the modern game, it is hard to imagine Giggs merely turning his back on it at a time when his overall influence is as high at it has ever been.[LNB]Giggs extended his record of scoring in every Premier League season with a volley against Newcastle last month and he was an influential figure in the subsequent victory over West Ham.[LNB]Sir Alex Ferguson recently suggested the Cardiff-born player, who was only ever eligible to play for Wales despite his appearance for England schoolboys, could continue until his was 40 such are his fitness levels.