Frank Lampard has hailed the role of Fabian Delph on Everton's relegation battle - crediting him with having a "big impact".
Delph returned to action in the home game against Manchester United after a thigh injury had ruled him out for the opening months of Lampard's tenure.
He has since been a regular in the first team, only missing the Merseyside derby as part of efforts to manage his comeback effectively.
READ MORE: Frank Lampard breaks silence over Dominic Calvert-Lewin transfer rumours amid Newcastle United claim
READ MORE: Everton have perfect opportunity to repay incredible fans and banish relegation fear
However, Delph now faces a battle to feature again this season after picking up a knock in the draw at Watford in midweek.
But heading into the final week of the Premier League season, Lampard has stressed the importance of the former Manchester City midfielder in Everton's climb out of the relegation places and into a position whereby they could be safe after Sunday's game at home to Brentford.
Delph added much-needed composure to the Blues side when he returned in the aftermath of the disastrous defeat at Burnley last month. Individual errors and a lack of discipline had proved costly as the team's slump persisted either side of the international break.
The 32-year-old had an immediate impact in the crucial Goodison Park victory over Manchester United and, in the five games in which he has featured on the pitch under Lampard, Everton are unbeaten and have picked up 11 points from the 15 available.
His involvement has been so significant, the Blues boss said: "If he doesn't kick one more ball again this season he has made a big impact for us and I'm very thankful for the work he has put in for us."
His comments came as it was revealed Delph would not be fit for the Brentford match and could miss Crystal Palace and Arsenal through a muscle injury.
Asked how significant his absence is, Lampard said: "It is a big blow because he has offered things I have mentioned every time [I have spoken about him] - the experience and the qualities he has brought. I'm thankful to him for that because, to be fair, when I came in I realised it was a bit of a story around Delphy here at the club, even with his quality. He came in and was injured and has been fighting to get fit and he has made an impact."
The 32-year-old is out of contract in the summer and Lampard has previously said he will "happily sit with him and talk about what his future looks like from my point of view" when the timing is appropriate, highlighting the priority was keeping Delph fit for as much of the run-in as possible.