Arsenal tour: Oxlade-Chamberlain, Walcott and Gibbs in spotlight

Arsenal wrapped up their preseason tour of California with a second straight win on Sunday, beating Mexican club Chivas 3-1.

That came after a 2-1 victory over the MLS All-Stars in San Jose and the Gunners fly back home after a trip that provided several positive talking points.

Here are five things we learned from Arsenal's American visit ...

This could be the year of The Ox

Alex Oxlade-Chamberlain has been the standout performer this summer, and his display against Chivas showed he's getting back to his best after a lengthy injury layoff.

"The Ox" is still looking for that real breakthrough season where he fully lives up to his potential, but is showing signs that this could be the one.

His goal against Chivas was delightful, going past one defender on the right flank, using an audacious touch to cut back inside another and then slotting a low left-footed finish inside the far post. He scored with a superb lob in the first preseason game at French club RC Lens and has served a reminder he should be a regular 10-goal scorer in the league.

"[He gives us] power, penetration. He has it all," Wenger said about Oxlade-Chamberlain after the game.

So while Arsenal reportedly pursue Riyad Mahrez, Oxlade-Chamberlain may finally be ready to prove he can have a similar impact as the Leicester star.

Walcott still not a natural striker

Theo Walcott is also hoping to return to his best this season, but still isn't looking like a reliable solution up front.

Walcott has yet to score a goal in three preseason games, despite being given the chance to lead the line in Olivier Giroud's absence. In contrast, 20-year-old academy product Chuba Akpom netted twice in two games in California after coming on as a sub.

Giroud is expected to miss the start of the season after an extended holiday, and Wenger has made it clear he's still searching for a top class striker in the transfer window. Walcott hasn't done much so far to make that search seem any less urgent.

Arsenal are set long-term at centre-back

Arsenal have short-term worries when it comes to the centre-back position but they could be set for the next decade once the likes of Rob Holding, 20, and Krystian Bielik, 18, gain more experience.

Per Mertesacker's knee injury and Gabriel Paulista's tonsillitis meant Calum Chambers was the most senior Arsenal centre-back on the U.S. trip -- at the age of 21. But Holding, the new signing from Bolton, and Bielik both showed a composure and ability to read the game that belies their age.

Wenger probably doesn't want to rely on either one at the start of the season and expects to bring in a more experienced replacement for Mertesacker. But that duo, along with Chambers, could eventually give Wenger a permanent solution to a long-standing weakness.

Reine-Adelaide knocking on the door

There are several youngsters who are hoping to replicate Alex Iwobi this season by making an impact on the first team, and Jeff Reine-Adelaide seems to be next in line. The French attacking midfielder, who has been described as "special" by Wenger, impressed at times after coming on as a substitute for both games in California, after starting at Lens.

Reine-Adelaide can play either as a No. 10 or on the wing and offers another dynamic option to the attack. Tricky winger Chris Willock is another exciting prospect, while Wenger acknowledged last week that United States international Gedion Zelalem needs more time to develop physically.

Debuchy and Gibbs are too good for the bench

Many had expected Mathieu Debuchy and Kieran Gibbs to leave the club this summer in search of more playing time after losing their starting spots to Hector Bellerin and Nacho Monreal. But both are still there, and both have looked good in preseason -- serving up a reminder that Wenger is spoilt for choice when it comes to his full-backs.

Debuchy, who went out on loan to Bordeaux in January, has looked especially impressive in his attacking play down the wing -- although he did clumsily give away a late penalty against Chivas. It remains to be seen if Debuchy and Gibbs are still at the Emirates after deadline day, as they should be attractive targets for plenty of Premier League clubs. But if they stay, Wenger should find a better way of rotating them into the lineup. They are too good to be wasted on the bench.