Mikel Arteta has received a major boost ahead of what could be Arsenal's biggest game of the season yet. The Gunners are preparing to face Villarreal in the second leg of the Europa League semi-finals at the Emirates Stadium on Thursday.

The Spanish manager could have two key players back in the fold with Kieran Tierney and Alexandre Lacazette both taking part in training with the rest of the first team squad. The duo have been important members of Arteta's first-team squad this season.

Tierney has missed the last seven games after suffering a knee injury during Arsenal's loss to Liverpool in early March. The club was initially fearful that the Scottish left-back might need surgery but that was not the case, and he has recovered pretty swiftly.

Lacazette, on the other hand, has missed the last three games after picking up a hamstring injury during the 1-1 draw against Fulham on Apr. 18. The French marksman was in top form for the Gunners before picking up the injury and the manager will be hoping that he can pick up from where he left off with crucial games coming up in both Europe and the Premier League.

Arteta had declared both players fit ahead of the first leg of the semi-finals in Spain, but the duo were not part of the squad making it clear that it was just mind games on the Arsenal manager's part. The duo also failed to make the bench for Arsenal's win over Newcastle United on Sunday with the Gunners boss labelling them a doubt for the second-leg.

"They haven't trained with the team yet so I think they're unlikely to be," Arteta said after the Newcastle game, as quoted on the Arsenal website.

However, their return to first-team training on Tuesday will change the status of their availability. But it remains to be seen if Arteta will risk both the players from the start, especially after he saw David Luiz suffer a muscular injury just 52 minutes into his comeback from a knee surgery.

Alexandre Lacazette
Alexandre Lacazette scored twice in Arsenal's 4-0 win at West Brom Michael Regan/POOL