Since Lewandowski's arrival at Camp Nou, Depay has rarely had minutes to play, so it's only natural that he hasn't contributed much to Barcelona which has made his market value also drop, but as an option to replace Lewandowski he's still quite good. But on the other hand, there is still no suitable replacement for Lewandowski's role, but the play-off round is still a long time away. We still don't know what will happen, let's just wait.
Robert Lewandowski have impressive performance with Barcelona and success become top scorer awhile with 13 goals in La Liga, I don't think Depay have chance to replace position from Lewandowski after biggest contribution until 14 matches. Still can't guarantee with Depay get regular position in Europe League trough Barcelona have important match in play off round against Manchester United, I think although success qualify to next round seems difficult for Depay get position in starting eleven.
Barcelona still have life and die match against Manchester United in play off round, due World Cup over and several player need recovery I don't think which one have favorite can win in this play off round match, but Manchester United have show with good performance after winning from Burnley at EFL Cup last night.
Regarding Manchester United in the European League play-off round, it seems that Barcelona will continue to use their flagship players and Lewandowski will be the spearhead of their main attack. Manchester United is eager to rise to its best performance and its victory over Burnley in the EFL is a good starting capital when playing their next competition.
If you are aware of it, Memphis Depay's elimination from Barcelona's main squad was not because Memphis Depay's performance was bad, but Memphis Depay was injured. But lucky for Depay, even though at Barcelona Depay was injured but when the World Cup started Memphis Depay had recovered from injury, so Memphis Depay was still able to play at the World Cup yesterday.
So, if Memphis Depay has recovered, it is very possible that Memphis Depay will be paired with Lewandowski for the Barcelona match later and of course it will be better in attack that Barcelona has.
But regarding Barcelona who will play against Manchester United in the play-off round, basically it is a difficult prediction.
Because Barcelona's performance is not balanced with the good results they have achieved in La Liga and also in Europe, because if Barcelona can make a more balanced performance between the two then I believe Barcelona will be able to beat Manchester United. But yes, this result is of course still uncertain, because if Xavi does not maintain his good performance then of course Barcelona will be knocked out of the Europa League again.