Alex provided the assist for Olivier Giroud's early goal against Aston Villa. However the winger received a knee injury just before half-time that would keep him out for the rest of the month.
A knee injury sustained in the opening-day loss to Aston Villa kept Alex out of contention for the whole of September.
A knee injury kept the Ox out of action for the whole of October.
A knee injury kept Alex out of action for the whole of November.
A knee injury kept Alex out of action for the whole of December.
After playing 45 minutes for the under-21s against Fulham, Alex made his long-awaited return to the first team when he came on as a late substitute against Aston Villa. His first start came in the FA Cup win over Coventry and he made two cameo appearances in the league games against Fulham and Southampton.
"I'm a bit tired and I'm not match fit yet," he told Arsenal Player after the Coventry match. "In the second half that showed a little bit in my performance but that will come.
"It was really nice to get back on the pitch from the start of the game tonight and a little run-out in midfield was nice for me as well. That's a stepping stone in the right direction for me and with a few more starts I should be back to match fitness."
After returning from injury in January, the Ox produced some outstanding displays in February. The Englishman scored a brace in the 2-0 win over Crystal Palace at the start of the month before netting Arsenal's opening goal in the 2-1 win against Liverpool. The 20-year-old also showed electric pace to beat his marker and set up Lukas Podolski's strike against Liverpool
"It's always an amazing feeling to score a goal, especially at a superb stadium like the Emirates," he said after the Palace game. "I'm glad to give something back to the fans. It's something that I want to add to my game more so it was nice to get two today."
The Ox started five of Arsenal's seven games in March and produced an eye-catching display in Allianz Arena with his pace and power creating some dangerous situations for the Bayern defence.
Alex was involved in Tomas Rosicky's early strike against Spurs but missed two opportunities to double the Gunners' lead in that game.
Speaking after the Champions League exit in Munich, the England international said: "It's a bit of a similar feeling to last season, but we can take pride out of the performance. To come here and get a 1-1 draw isn't what we wanted but we put in a really good shift against a really tough Bayern side."
Alex made one appearance in August, playing 18 minutes as a second-half substitute in the goalless draw at Stoke. “In training I'm seeing the likes of Lukas Podolski and Olivier Giroud, and then we have Gervinho and Theo Walcott too, so it's looking really good,” said the teenager. “That brings strong and healthy competition, which can only push us on to do well."
Alex featured four times in September. The winger scored against Coventry in the Capital One Cup, smashing home an unstoppable shot from outside the penalty area.
After starting against Olympiacos in the Champions League, Alex injured his hip in his next appearance, the 1-0 loss at Carrow Road, and did not appear again in October.
Alex made four appearances in November, starting against Montpellier and Aston Villa.
Alex featured in all seven of Arsenal’s fixtures in December. He won a penalty against West Brom and was named man of the match for an outstanding performance at Wigan Athletic. He ended 2012 by scoring his first Premier League goal in the win over Newcastle United. Alex also signed a new contract at the Club, along with Jack Wilshere, Kieran Gibbs, Carl Jenkinson and Aaron Ramsey.
Alex made four appearances in January, three of which were starts. Laurent Koscielny’s early red card against Manchester City meant the youngster was substituted by Per Mertesacker just 12 minutes into the game.
Alex started against Stoke City and Blackburn Rovers. He was an unused substitute in Arsenal’s other three games.
"I always want people to be watching me and I like it when people tell me I need to be doing more,” the teenager said. “It gives me more motivation to go out and there, roll up my sleeves and prove to them that they can knock me down, but I’m going to keep going and keep proving that I can play and I can do well."
Alex was a late substitute in Munich before starting against Swansea City. The England international was in fine form at Liberty Stadium and twice struck the crossbar as Arsenal secured a 2-0 victory. Alex came off the bench against Reading and won the penalty that Mikel Arteta converted in the closing stages.
Alex made three appearances in April, coming off the bench against Norwich City, Everton and Manchester United. The midfielder set up Olivier Giroud’s goal to put Arsenal into the lead against the Canaries.
Having been brought off the bench in the closing stages of the wins over Queens Park Rangers and Wigan Athletic, Alex was introduced in the opening half hour in Arsenal's final game of the season, at Newcastle United. After coming on for Mikel Arteta, the 19-year-old produced an energetic performance in the heart of midfield as Arsenal secured a top-four finish. "I've been waiting for any sort of chance to play and I've been getting a few minutes off the bench so to be able to come on in the first half was a bit of a surprise," he told Arsenal Player after victory at St James' Park. "I was aware that Mikel might have struggled a bit so mentally I prepared as if I was going to start the game. That helped me."
Alex joined the Club in August. The teenager became Arsène Wenger’s third acquisition of the summer and put pen to paper on a long-term contract after his transfer from Southampton. He was an unused substitute against Newcastle and Liverpool before making his Arsenal debut at Old Trafford as a late sub.
It was a whirlwind month for Alex, who scored in both his appearances. The young winger hit a cracker to help beat Shrewsbury and opened the scoring against Olympiacos in the Champions League. “I always used to watch Arsenal and I loved the way they played football,” he said. “I think it was the manager, stadium and fans that sold it for me."
Alex featured once during the month, starting the Carling Cup clash against Bolton to help the Gunners make it through to the competition's last eight.
Alex's exciting reputation was fuelled once more with a man-of-the-match display against Manchester City in the Carling Cup.
Alex forced his way into the majority of Arsene Wenger's Premier League squads over the month without featuring. He did, however, impress in the team's Champions League defeat to Olympiacos at the beginning of December.
Alex started three matches for the Gunners during the month - playing a starring role against Manchester United - and made one substitute's appearance. "He looks to have [the same fearlessness as Rooney]," said Arsene Wenger. "Now he has to show that he can play all the time but I believe he can. We have produced more players in the last 15 years than all of the top clubs in Europe put together and we are not scared to play players when they are of the level. I believe he has [that level]."
Alex featured six times over the course of the month, and scored his first Premier League goals in the 7-1 defeat of Blackburn. “He’s not someone who thinks about negatives, just positives and you can enjoy the game like that. I had that as well when I was younger,” Robin van Persie said about the teenager.
Alex played his part in an excellent month for Arsenal, featuring in five of the team’s six matches. He impressed in a central role against Italian champions AC Milan before starting against Newcastle six days later. “I just feel part of the squad now, I am really comfortable with all of the lads, the fans and feel a massive part of it," said the 18-year-old. “Maybe not so much now but I can see myself being a part of Arsenal's future. That is where I would like to be anyway and I am going to work as hard as I can to make sure I achieve that."
Alex featured in all but one of Arsenal's matches but was used mainly off the bench. His one start came in the goalless draw against Chelsea after substitute appearances against Manchester City, Wolves and Wigan.
Alex appeared as a second-half substitute in the 3-3 draw against Norwich.