Jos Buttler played his part in England's thrilling victory against Pakistan believing that if he didn't make runs, he was probably playing his last Test.

Buttler made the frank admission after scoring 75 and sharing a century stand with Chris Woakes, who finished not out on 84, to help England chase down an imposing fourth-innings target of 277 with three wickets in hand and a day to spare.

It came as Buttler faced increasing criticism over his batting - his Test average had dropped to 31.63 going into this, his 45th Test - and he had a poor game behind the stumps, missing three chances during Pakistan's first innings.

"If I'd taken those chances, we'd have won two hours ago," Buttler told Sky Sports after play. "I'm very aware I didn't keep well, I missed some chances and at this level you can't afford to do that no matter how many runs you score. You've got to be better, I know that.

"Definitely thoughts go through your head, like potentially if I don't score any runs I've probably played my last game. Those kind of things are in your head, but you've got to try and shut them out and try and focus on the here and now and play the situation and I'm pleased that I was able to do that."

Buttler's Test average since the start of 2019 was even worse at 24.46, with four half-centuries going into this match. He showed glimpses of improvement with 67 in England's series-deciding third-Test win against West Indies, and 38 out of an under-par 217 in the first innings against Pakistan.

Buttler's errors behind the stumps were undeniably costly, a dropped catch and missed stumping twice letting off Shan Masood on 45 before he went on to top score for the match with 156. He also missed a run-out chance with a wayward throw in Pakistan's first innings. And while the mistakes didn't ultimately affect the result, they contributed to England being under huge pressure as they were asked to post the second-highest successful fourth-innings chase at Old Trafford.

Buttler's status as a great of the white-ball game has not been questioned and those credentials came in handy during England's pursuit. In fact, his captain, Joe Root, called upon Buttler's skill in that area when he came in with his side 106 for 4, having lost Ben Stokes and still needing 171 runs.

The tempo of the run chase became particularly important because, Buttler said, he wanted to "take the new ball out of the equation" by guiding England as close to the target as possible before it became available, especially with the pitch misbehaving at times.

Ollie Pope saw that first-hand, so to speak, when he gloved a Shaheen Shah Afridi ball that reared off a length to gully.

"After I saw that ball to Popey it felt like if you just try and stay in and bat the time you're going to be a bit of a sitting duck," Buttler said. "So I wanted to be positive, try and put pressure back on Pakistan and try and replicate a one-day chase.

"In terms of how many overs was it till the new ball, if we were going to get close we didn't want to leave, say, 50 with the new ball to come. I thought that was going be tough work, having a harder ball, seeing the indifferent bounce, so try and break it down to try and score at four an over."

The plan worked. By the time Pakistan took the second new ball, England needed just 13 runs to win and, although Buttler was out by then, he had left his side in a strong position and in the capable hands of Woakes.

Butter later told a press conference: "Joe actually said before, 'remember who you are, you enjoy chasing targets down, try to limit it to a one-day game'.

"A game like today really suited me and suited my eye, in terms of the run chase and breaking it down to more of a one-day game and trying to tick runs off and get us to the finishing line."

Buttler also revealed that his belief had faltered "at times" recently as his place as England's first-choice keeper-batsman came increasingly up for debate.

"There have been some lonely nights thinking about it," Buttler said. "But runs aside, if you are a wicketkeeper in this team, you have to take chances. You have to keep better than I did in the first innings. I know that. I don't need other people to tell me that. I expect it of myself and to play international cricket for England there's a level required."

Not only did victory come with doubts swirling around his own performances, it also came at a time of off-field turmoil for Buttler, whose father was admitted to hospital after watching the day's play on Friday, following a run of recent health scares. He was allowed to return home on Saturday, and Root was full of praise for Buttler's fortitude.

"It says a huge amount about him as a person, to be able to carry that, and to be able to use that or park that going into this innings," Root said. "Only he will know which way around he did that. But I'm sure it's very difficult thing not to think about. To be able to deal with that and still play in that manner was exceptional.

"One of his big traits is that, under pressure, he puts in big performances. Another example of that was that final ODI against Australia on this very ground. You can deal with those high-pressure situations but to have that external pressure as well, I'm chuffed to bits for him, it must have been very difficult to deal with."