LONDON • Players of the calibre of Alexis Sanchez do not become available very often so Manchester United had no choice but to make a move for the Chilean, former Ireland defender Denis Irwin has said.

"When a player of that ability comes along, I think you (have) got to be in the market for him," Irwin, who played more than 500 games for United during 12 trophy-laden seasons, told Reuters.

Sanchez, 29, has scored 60 goals in 122 Premier League appearances for Arsenal since joining from Barcelona for £35 million (S$64.2 million) in July 2014.

That equates to 0.49 goals a match, or a goal in every two matches for the forward.

Comparatively, that statistic is slightly higher than United's main striker Romelu Lukaku (0.46 goals a match or 96 goals in 209 appearances).

"He's an experienced international. He's quick, he's strong," Irwin added. "He would not just add to our squad but our team. He's a really good player and I think he will be a good addition, really good."

Irwin also lauded United manager Jose Mourinho's ability to attract top players and said the Portuguese had done enough to warrant an extension to the three-year contract he signed in 2016.

"Since he's come in 16-17 months back, he's brought in some really good players," said the former left-back, who was one of Alex Ferguson's key players.

"He attracts good players and all of them have strengthened us. I feel we are lot more competitive that 16 months ago.

"Two trophies (League Cup and Europa League) last season, progression on the field, we are getting better and stronger. Why not (give him an extension)?"

REUTERS