The midfielder completed his transfer to the Reds from Arsenal on deadline day last week after he opted to leave The Emirates after six years with the club.
Oxlade-Chamberlain will be hoping to prove himself as worthy as a spot in the first team at Liverpool as the Reds prepare to take on Manchester City in their next Premier League game at The Etihad on Saturday.
And the England star looked to be in good spirits as he walked out at Melwood for the first time alongside Jordan Henderson.
Liverpool head into their clash with Manchester City on the back of their 4-0 thrashing of Arsenal at Anfield, a game in which Oxlade-Chamberlain featured for the Gunners.
The Reds are also preparing for a return to the Champions League group stage this season, starting next week.
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