Nery Castillo: Devil in the detail as Castillo pays for his City break

It seems unthinkable that Nery Castillo the man known to the Mexican nation as El Diablo (the devil), who revealed his genius with the three exquisite left-foot touches which famously carved a goal out of the Brazilian defence in last summer's Copa America could have experienced despair in his footballing life. But that, Sven Goran Eriksson observed yesterday, is precisely the emotion he discovered in the forward, who was bereft of football and spirit at Shakhtar Donetsk last month.

"Desperate," Eriksson observed, with a shake of his head. "He was desperate to come to us, desperate to come to England, desperate to come to the Premier League." So desperate to leave Donetsk, in fact, that when the Ukrainian side seemed to have scuppered the prospect of a loan deal to City with demands for a 3m payment, the Mexican stumped up half the fee himself. Eriksson has seen plenty in his time in football but a player paying out of his own pocket to move to a club? "No," he said. "I've never seen it before."

The frustrations have continued since Castillo a source of even more excitement among City fans than that other recent Donetsk recruit, Elano Blumer arrived in Manchester three weeks ago. Registration delays in London have stalled his City career until today, when he is widely expected to play from the start in the side's FA Cup tie at West Ham.

But Eriksson, whom sources suggest may have completed the signature of an additional big name striker by this time next week, clearly sees him as a fulcrum of what he described yesterday as his "project" at Eastlands. "A player like Castillo will help us now, but he is such a good player he will be important for us for our future," Eriksson said. "He's technically very good, he has a lot of pace and he's tactically very good as well. He's been playing second striker, he's been playing first striker, he's been playing right and left."

To some, Castillo might look a touch on the slight side for the physical challenge of the Premier League ("no problem; he's very fit," Eriksson insists), but ask around the staff who have seen him training at City's Carrington base this week and they will tell you that it is his pace which is most thrilling. The fans have seen much the same through watching his exploits in the No 21 jersey for Mexico.

For a player who had trials at Manchester United a few years ago and has pictures of himself with Sir Alex Ferguson to prove it his choice of clubs to date has been curious. Castillo's nationality is complex. He was born in San Luis Potosi, Mexico, moved to his father's native Uruguay, but was tempted to play for El Tri in an inspired move by Mexico coach Hugo Sanchez. But few expected him to become the first and only Mexican to play professionally in Greece, where a close friendship with City's Georgios Samaras was cemented, then leave Olympiacos for a Ukrainian club even further removed from his roots.

Life has not been easy at either place. In his seven-season stint at Olympiacos he scored 30 goals in just over 100 games, but with Rivaldo joining the club, found first-team chances limited before reclaiming a place last season and scoring 12 in 25 games. Elano left Shakhtar on the day Castillo walked in, telling the Mexican that life in the freezing Ukraine would not be easy. "You'll never last here. Wait until the weather gets bad," he said. But nobody could have predicted what was to follow for the 10m signing. He had struggled for game time when, in only his eighth match, he fell out spectacularly with coach Mircea Lucescu by refusing to hand over the ball to regular penalty-taker Cristiano Lucarelli after Donetsk were awarded a spot-kick during a league game. Badly wanting to break his duck after seven blanks, Castillo took the penalty himself, missed, was immediately substituted and never played for the club again.

As only the second Mexican player to sign for a Premier League team his predecessor Jared Borgetti hardly set the world alight at Bolton Castillo has something to prove.

Yesterday Eriksson did not dismiss out of hand suggestions that he might also try to bring Roque Santa Cruz to Eastlands. He has also sent Danny Mills out on loan to Derby and told Andreas Isaksson who may be beaten to a place on the bench by Kasper Schmeichel, who has returned from a successful loan spell at Cardiff, today that he is free to leave City.

Eriksson also reflected on the greater prospect of FA Cup success which he believes Castillo can help bring him.

"It is beautiful and to sit in on the bench at Wembley in your suit with a rose in the lapel," he said. "It would be very nice."