Arsenal could be without a few key players for their Europa League semi-final second leg against Villarreal on Thursday, according to Mikel Arteta but Kieran Tierney and Alexandre Lacazette back in training was a welcome site.

With Pierre-Emerick Aubameyang, Martin Odegaard, and David Luiz returning to Arsenal’s starting lineup last week, Arsenal’s senior injury list was briefly down to just two players – Alexandre Lacazette and Kieran Tierney.

Unfortunately, Luiz then got injured during the match against Newcastle United, and the early signs are that it looks like he’ll miss the Villarreal second leg however the injury may not be as bad as first feared.

“He felt something in his hamstring so it’s not good news,” Mikel Arteta said afterwards. “He’s put in such a shift to be back with the team for the last few weeks after the knee surgery. It’s a real shame.”

As for the other two, Lacazette and Tierney, Arteta didn’t entirely rule them out of Thursday’s game.

However, even though Mikel Arteta suggested that neither of them are likely to make it back in time, both were pictured taking part in full training on Tuesday:

“They haven’t trained with the team yet, so I think they’re unlikely to be (available),” Arteta said on Monday.

Up front, this isn’t totally disastrous news, given Aubameyang is back and scoring again. The bigger problem is in midfield, with Dani Ceballos suspended and Granit Xhaka now likely to have to play at left-back.

It would make a big difference having Tierney at left-back and Xhaka in midfield, but the odds are against that happening at this stage.