Mikel Arteta praised the display of debutant Pablo Mari as the Gunners new boy helped keep a clean sheet on his first experience of English football.
Centre-back Mari - who used to be on the books at Manchester City , where he never played a senior game - signed for the Gunners on loan from Flamengo in January, with the deal expected to be made permanent in the summer.
The Spaniard helped keep a clean sheet as a largely youthful Gunners side eased past League One Portsmouth 2-0 in the FA Cup thanks to goals from Sokratis Papastathopoulos and Eddie Nketiah either side of half-time.
And Arteta was happy with the performance of the new addition, whose communication skills were praised.
"I think he looked comfortable," he told the Gunners website .
"He is very vocal and very comfortable on the ball, always commanding the back four and he looked like he’s played here for months. I think we have a good player.
‘We didn’t see the lack of rhythm that he has because he hasn’t played in two-and-a-half months I think but in general, overall, really happy."
Arteta was also delighted with the display of his young players at Fratton Park, particular after a start in which the Gunners didn't look at their fluid best.
"To come here, to this stadium, with seven under-23 players, and to dominate completely is a little bit unrealistic but we went through that moment [at the start] and after that we started to take the ball and play in the opposition half and dominate the situation much better," he continued.
"We scored the goals and should have scored more."
